dovecot-submission SMTP send error with Thunderbird (BODY=8BITMIME)

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dovecot-submission SMTP send error with Thunderbird (BODY=8BITMIME)

Reuben Farrelly-7
Hi,

With latest 2.3 -git (and 2.3.0 release), I'm running into this error
with Thunderbird:

"An error occurred while sending mail. The mail server responded: 5.5.4
Unsupported mail BODY type. Please verify that your email address is
correct in your account settings and try again."

This is fatal and means Thunderbird cannot use the submission service -
fortunately I can revert back to a native Postfix service which works.

Here's a tcpdump of the conversation:

thunderstorm /etc/dovecot/conf.d # tcpdump -A port 587

dropped privs to tcpdump
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes


14:12:19.975982 IP6 2001:44b8:31d4:1311:45ec:e191:8093:3e9d.61175 >
inside-mail.reub.net.submission: Flags [S], seq 572328223, win 64800,
options [mss 1440,nop,wscale 8,nop,nop,sackOK], length 0
`._.. .? .D.1...E.....>. .D.1..........#...K".  ........ .w..............
14:12:19.976022 IP6 inside-mail.reub.net.submission >
2001:44b8:31d4:1311:45ec:e191:8093:3e9d.61175: Flags [S.], seq
3954361671, ack 572328224, win 28800, options [mss
1440,nop,nop,sackOK,nop,wscale 7], length 0
`.c|. .@ .D.1..........# .D.1...E.....>..K.....G". ..p.:4..............
14:12:19.976158 IP6 2001:44b8:31d4:1311:45ec:e191:8093:3e9d.61175 >
inside-mail.reub.net.submission: Flags [.], ack 1, win 8235, length 0
`._....? .D.1...E.....>. .D.1..........#...K".   ...HP. +. ..
14:12:19.983409 IP6 inside-mail.reub.net.submission >
2001:44b8:31d4:1311:45ec:e191:8093:3e9d.61175: Flags [P.], seq 1:43, ack
1, win 225, length 42
`.c|.>.@ .D.1..........# .D.1...E.....>..K.....H".       P...:R..220
thunderstorm.reub.net Dovecot ready.

14:12:19.992790 IP6 2001:44b8:31d4:1311:45ec:e191:8093:3e9d.61175 >
inside-mail.reub.net.submission: Flags [P.], seq 1:54, ack 43, win 8234,
length 53
`._..I.? .D.1...E.....>. .D.1..........#...K".   ...rP. *.H..EHLO
[IPv6:2001:44b8:31d4:1311:45ec:e191:8093:3e9d]

14:12:19.992828 IP6 inside-mail.reub.net.submission >
2001:44b8:31d4:1311:45ec:e191:8093:3e9d.61175: Flags [.], ack 54, win
225, length 0
`.c|...@ .D.1..........# .D.1...E.....>..K.....r".      UP...:(..
14:12:19.993027 IP6 inside-mail.reub.net.submission >
2001:44b8:31d4:1311:45ec:e191:8093:3e9d.61175: Flags [P.], seq 43:200,
ack 54, win 225, length 157
`.c|...@ .D.1..........# .D.1...E.....>..K.....r".
UP...:...250-thunderstorm.reub.net
250-8BITMIME
250-AUTH PLAIN LOGIN
250-BURL imap
250-CHUNKING
250-ENHANCEDSTATUSCODES
250-SIZE
250-STARTTLS
250 PIPELINING

14:12:20.015953 IP6 2001:44b8:31d4:1311:45ec:e191:8093:3e9d.61175 >
inside-mail.reub.net.submission: Flags [P.], seq 54:91, ack 200, win
8234, length 37
`._..9.? .D.1...E.....>. .D.1..........#...K".  U....P. *....AUTH PLAIN xxxx

14:12:20.035676 IP6 inside-mail.reub.net.submission >
2001:44b8:31d4:1311:45ec:e191:8093:3e9d.61175: Flags [P.], seq 200:222,
ack 91, win 225, length 22
`.c|.*.@ .D.1..........# .D.1...E.....>..K......".      zP...:>..235
2.7.0 Logged in.

14:12:20.036642 IP6 2001:44b8:31d4:1311:45ec:e191:8093:3e9d.61175 >
inside-mail.reub.net.submission: Flags [P.], seq 91:143, ack 222, win
8234, length 52
`._..H.? .D.1...E.....>. .D.1..........#...K".  z...%P. *....MAIL
FROM:<[hidden email]> BODY=8BITMIME SIZE=444

14:12:20.036826 IP6 inside-mail.reub.net.submission >
2001:44b8:31d4:1311:45ec:e191:8093:3e9d.61175: Flags [P.], seq 222:260,
ack 143, win 225, length 38
`.c|.:.@ .D.1..........# .D.1...E.....>..K.....%".      .P...:N..555
5.5.4 Unsupported mail BODY type

14:12:20.089196 IP6 2001:44b8:31d4:1311:45ec:e191:8093:3e9d.61175 >
inside-mail.reub.net.submission: Flags [.], ack 260, win 8233, length 0
`._....? .D.1...E.....>. .D.1..........#...K".  ....KP. )....


Curiously enabling rawlog doesn't capture this error, which is why I
used tcpdump above.  The logs from it like this:

thunderstorm /run/dovecot/rawlogs # cat 20171219-141149.5633.1.in
1513653109.109030 220 thunderstorm.reub.net ESMTP Postfix (3.3-20171028)
1513653109.109266 250-thunderstorm.reub.net
1513653109.109266 250-PIPELINING
1513653109.109266 250-SIZE 40960000
1513653109.109266 250-VRFY
1513653109.109266 250-ETRN
1513653109.109266 250-STARTTLS
1513653109.109266 250-ENHANCEDSTATUSCODES
1513653109.109266 250-8BITMIME
1513653109.109266 250-DSN
1513653109.109266 250 SMTPUTF8
1513653130.973720 221 2.0.0 Bye

thunderstorm /run/dovecot/rawlogs # cat 20171219-141149.5633.1.out
1513653109.109087 EHLO thunderstorm.reub.net
1513653130.973351 QUIT
1513653130.973829 QUIT
thunderstorm /run/dovecot/rawlogs #

This with:

# Write protocol logs for relay connection to this directory for debugging
#submission_relay_rawlog_dir =
submission_relay_rawlog_dir = /run/dovecot/rawlogs/

Is this a separate but unrelated problem with rawlog support in this the
submission?  I would have expected it to capture the full conversation
log including any protocol errors and failures like this.

Reuben
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Re: dovecot-submission SMTP send error with Thunderbird (BODY=8BITMIME)

Aki Tuomi-2
Hi, thank you for your report. We'll look into it!

Aki

> On December 23, 2017 at 8:18 AM Reuben Farrelly <[hidden email]> wrote:
>
>
> Hi,
>
> With latest 2.3 -git (and 2.3.0 release), I'm running into this error
> with Thunderbird:
>
> "An error occurred while sending mail. The mail server responded: 5.5.4
> Unsupported mail BODY type. Please verify that your email address is
> correct in your account settings and try again."
>
> This is fatal and means Thunderbird cannot use the submission service -
> fortunately I can revert back to a native Postfix service which works.
>
> Here's a tcpdump of the conversation:
>
> thunderstorm /etc/dovecot/conf.d # tcpdump -A port 587
>
> dropped privs to tcpdump
> tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
> listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes
>
>
> 14:12:19.975982 IP6 2001:44b8:31d4:1311:45ec:e191:8093:3e9d.61175 >
> inside-mail.reub.net.submission: Flags [S], seq 572328223, win 64800,
> options [mss 1440,nop,wscale 8,nop,nop,sackOK], length 0
> `._.. .? .D.1...E.....>. .D.1..........#...K".  ........ .w..............
> 14:12:19.976022 IP6 inside-mail.reub.net.submission >
> 2001:44b8:31d4:1311:45ec:e191:8093:3e9d.61175: Flags [S.], seq
> 3954361671, ack 572328224, win 28800, options [mss
> 1440,nop,nop,sackOK,nop,wscale 7], length 0
> `.c|. .@ .D.1..........# .D.1...E.....>..K.....G". ..p.:4..............
> 14:12:19.976158 IP6 2001:44b8:31d4:1311:45ec:e191:8093:3e9d.61175 >
> inside-mail.reub.net.submission: Flags [.], ack 1, win 8235, length 0
> `._....? .D.1...E.....>. .D.1..........#...K".   ...HP. +. ..
> 14:12:19.983409 IP6 inside-mail.reub.net.submission >
> 2001:44b8:31d4:1311:45ec:e191:8093:3e9d.61175: Flags [P.], seq 1:43, ack
> 1, win 225, length 42
> `.c|.>.@ .D.1..........# .D.1...E.....>..K.....H".       P...:R..220
> thunderstorm.reub.net Dovecot ready.
>
> 14:12:19.992790 IP6 2001:44b8:31d4:1311:45ec:e191:8093:3e9d.61175 >
> inside-mail.reub.net.submission: Flags [P.], seq 1:54, ack 43, win 8234,
> length 53
> `._..I.? .D.1...E.....>. .D.1..........#...K".   ...rP. *.H..EHLO
> [IPv6:2001:44b8:31d4:1311:45ec:e191:8093:3e9d]
>
> 14:12:19.992828 IP6 inside-mail.reub.net.submission >
> 2001:44b8:31d4:1311:45ec:e191:8093:3e9d.61175: Flags [.], ack 54, win
> 225, length 0
> `.c|...@ .D.1..........# .D.1...E.....>..K.....r".      UP...:(..
> 14:12:19.993027 IP6 inside-mail.reub.net.submission >
> 2001:44b8:31d4:1311:45ec:e191:8093:3e9d.61175: Flags [P.], seq 43:200,
> ack 54, win 225, length 157
> `.c|...@ .D.1..........# .D.1...E.....>..K.....r".
> UP...:...250-thunderstorm.reub.net
> 250-8BITMIME
> 250-AUTH PLAIN LOGIN
> 250-BURL imap
> 250-CHUNKING
> 250-ENHANCEDSTATUSCODES
> 250-SIZE
> 250-STARTTLS
> 250 PIPELINING
>
> 14:12:20.015953 IP6 2001:44b8:31d4:1311:45ec:e191:8093:3e9d.61175 >
> inside-mail.reub.net.submission: Flags [P.], seq 54:91, ack 200, win
> 8234, length 37
> `._..9.? .D.1...E.....>. .D.1..........#...K".  U....P. *....AUTH PLAIN xxxx
>
> 14:12:20.035676 IP6 inside-mail.reub.net.submission >
> 2001:44b8:31d4:1311:45ec:e191:8093:3e9d.61175: Flags [P.], seq 200:222,
> ack 91, win 225, length 22
> `.c|.*.@ .D.1..........# .D.1...E.....>..K......".      zP...:>..235
> 2.7.0 Logged in.
>
> 14:12:20.036642 IP6 2001:44b8:31d4:1311:45ec:e191:8093:3e9d.61175 >
> inside-mail.reub.net.submission: Flags [P.], seq 91:143, ack 222, win
> 8234, length 52
> `._..H.? .D.1...E.....>. .D.1..........#...K".  z...%P. *....MAIL
> FROM:<[hidden email]> BODY=8BITMIME SIZE=444
>
> 14:12:20.036826 IP6 inside-mail.reub.net.submission >
> 2001:44b8:31d4:1311:45ec:e191:8093:3e9d.61175: Flags [P.], seq 222:260,
> ack 143, win 225, length 38
> `.c|.:.@ .D.1..........# .D.1...E.....>..K.....%".      .P...:N..555
> 5.5.4 Unsupported mail BODY type
>
> 14:12:20.089196 IP6 2001:44b8:31d4:1311:45ec:e191:8093:3e9d.61175 >
> inside-mail.reub.net.submission: Flags [.], ack 260, win 8233, length 0
> `._....? .D.1...E.....>. .D.1..........#...K".  ....KP. )....
>
>
> Curiously enabling rawlog doesn't capture this error, which is why I
> used tcpdump above.  The logs from it like this:
>
> thunderstorm /run/dovecot/rawlogs # cat 20171219-141149.5633.1.in
> 1513653109.109030 220 thunderstorm.reub.net ESMTP Postfix (3.3-20171028)
> 1513653109.109266 250-thunderstorm.reub.net
> 1513653109.109266 250-PIPELINING
> 1513653109.109266 250-SIZE 40960000
> 1513653109.109266 250-VRFY
> 1513653109.109266 250-ETRN
> 1513653109.109266 250-STARTTLS
> 1513653109.109266 250-ENHANCEDSTATUSCODES
> 1513653109.109266 250-8BITMIME
> 1513653109.109266 250-DSN
> 1513653109.109266 250 SMTPUTF8
> 1513653130.973720 221 2.0.0 Bye
>
> thunderstorm /run/dovecot/rawlogs # cat 20171219-141149.5633.1.out
> 1513653109.109087 EHLO thunderstorm.reub.net
> 1513653130.973351 QUIT
> 1513653130.973829 QUIT
> thunderstorm /run/dovecot/rawlogs #
>
> This with:
>
> # Write protocol logs for relay connection to this directory for debugging
> #submission_relay_rawlog_dir =
> submission_relay_rawlog_dir = /run/dovecot/rawlogs/
>
> Is this a separate but unrelated problem with rawlog support in this the
> submission?  I would have expected it to capture the full conversation
> log including any protocol errors and failures like this.
>
> Reuben
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Re: dovecot-submission SMTP send error with Thunderbird (BODY=8BITMIME)

Stephan Bosch-2
In reply to this post by Reuben Farrelly-7
Op 12/23/2017 om 7:18 AM schreef Reuben Farrelly:

> Hi,
>
> With latest 2.3 -git (and 2.3.0 release), I'm running into this error
> with Thunderbird:
>
> "An error occurred while sending mail. The mail server responded:
> 5.5.4 Unsupported mail BODY type. Please verify that your email
> address is correct in your account settings and try again."
>
> This is fatal and means Thunderbird cannot use the submission service
> - fortunately I can revert back to a native Postfix service which works.
>
> Here's a tcpdump of the conversation:
>
> thunderstorm /etc/dovecot/conf.d # tcpdump -A port 587
>
> dropped privs to tcpdump
> tcpdump: verbose output suppressed, use -v or -vv for full protocol
> decode
> listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes

I cannot reproduce this behavior so far.

(ngrep -Wbyline produces more readable output)

> Curiously enabling rawlog doesn't capture this error, which is why I
> used tcpdump above.  The logs from it like this:
>
> thunderstorm /run/dovecot/rawlogs # cat 20171219-141149.5633.1.in
> 1513653109.109030 220 thunderstorm.reub.net ESMTP Postfix (3.3-20171028)
> 1513653109.109266 250-thunderstorm.reub.net
> 1513653109.109266 250-PIPELINING
> 1513653109.109266 250-SIZE 40960000
> 1513653109.109266 250-VRFY
> 1513653109.109266 250-ETRN
> 1513653109.109266 250-STARTTLS
> 1513653109.109266 250-ENHANCEDSTATUSCODES
> 1513653109.109266 250-8BITMIME
> 1513653109.109266 250-DSN
> 1513653109.109266 250 SMTPUTF8
> 1513653130.973720 221 2.0.0 Bye
>
> thunderstorm /run/dovecot/rawlogs # cat 20171219-141149.5633.1.out
> 1513653109.109087 EHLO thunderstorm.reub.net
> 1513653130.973351 QUIT
> 1513653130.973829 QUIT
> thunderstorm /run/dovecot/rawlogs #

Double QUIT. That is a minor bug, but not related.

>
> This with:
>
> # Write protocol logs for relay connection to this directory for
> debugging
> #submission_relay_rawlog_dir =
> submission_relay_rawlog_dir = /run/dovecot/rawlogs/
>
> Is this a separate but unrelated problem with rawlog support in this
> the submission?  I would have expected it to capture the full
> conversation log including any protocol errors and failures like this.

No. This is the connection with the relay (backend MTA) server. Use the
normal Dovecot rawlog facilities to capture protocol interaction with
the client instead.

Well, now we do know for sure that Dovecot is responsible for the error,
since the interaction with the relay server shows no issues.

I will continue experimenting a bit. I still have to actually try this
with Thunderbird. Any other configuration I should know about (`dovecot
-n`)?

Regards,

Stephan.

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Re: dovecot-submission SMTP send error with Thunderbird (BODY=8BITMIME)

Reuben Farrelly-7
Hi again,

On 24/12/2017 7:11 am, Stephan Bosch wrote:

> Op 12/23/2017 om 7:18 AM schreef Reuben Farrelly:
>> Hi,
>>
>> With latest 2.3 -git (and 2.3.0 release), I'm running into this error
>> with Thunderbird:
>>
>> "An error occurred while sending mail. The mail server responded:
>> 5.5.4 Unsupported mail BODY type. Please verify that your email
>> address is correct in your account settings and try again."
>>
>> This is fatal and means Thunderbird cannot use the submission service
>> - fortunately I can revert back to a native Postfix service which works.
>>
>> Here's a tcpdump of the conversation:
>>
>> thunderstorm /etc/dovecot/conf.d # tcpdump -A port 587
>>
>> dropped privs to tcpdump
>> tcpdump: verbose output suppressed, use -v or -vv for full protocol
>> decode
>> listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes
>
> I cannot reproduce this behavior so far.

The odd thing is, I can 100% of the time reproduce this with the client,
but 100% not reproduce it if I put the commands in by hand, at least up
to the MAIL FROM: part of the conversation.

Here's the TB log:

[Main Thread]: I/SMTP SMTP Connecting to: smtp.reub.net:587
[Main Thread]: I/SMTP SMTP entering state: 0
[Main Thread]: I/SMTP SMTP Response: 220 thunderstorm.reub.net Dovecot
ready.
[Main Thread]: I/SMTP SMTP entering state: 14
[Main Thread]: I/SMTP SMTP Send: EHLO
[IPv6:2001:44b8:31d4:1311:c0c8:3064:a55b:ae82]

[Main Thread]: I/SMTP SMTP entering state: 0
[Main Thread]: I/SMTP SMTP Response: 250-thunderstorm.reub.net
[Main Thread]: I/SMTP SMTP entering state: 0
[Main Thread]: I/SMTP SMTP Response: 250-8BITMIME
[Main Thread]: I/SMTP SMTP entering state: 0
[Main Thread]: I/SMTP SMTP Response: 250-AUTH PLAIN LOGIN
[Main Thread]: I/SMTP SMTP entering state: 0
[Main Thread]: I/SMTP SMTP Response: 250-BURL imap
[Main Thread]: I/SMTP SMTP entering state: 0
[Main Thread]: I/SMTP SMTP Response: 250-CHUNKING
[Main Thread]: I/SMTP SMTP entering state: 0
[Main Thread]: I/SMTP SMTP Response: 250-ENHANCEDSTATUSCODES
[Main Thread]: I/SMTP SMTP entering state: 0
[Main Thread]: I/SMTP SMTP Response: 250-SIZE
[Main Thread]: I/SMTP SMTP entering state: 0
[Main Thread]: I/SMTP SMTP Response: 250-STARTTLS
[Main Thread]: I/SMTP SMTP entering state: 0
[Main Thread]: I/SMTP SMTP Response: 250 PIPELINING
[Main Thread]: I/SMTP SMTP entering state: 4
[Main Thread]: I/SMTP SMTP entering state: 21
[Main Thread]: D/SMTP SMTP auth: server caps 0x20338, pref 0x300, failed
0x0, avail caps 0x300
[Main Thread]: D/SMTP (GSSAPI = 0x800, CRAM = 0x2000, NTLM = 0x4000, MSN
=  0x8000, PLAIN = 0x200, LOGIN = 0x100, EXTERNAL = 0x400)
[Main Thread]: D/SMTP trying auth method 0x200
[Main Thread]: I/SMTP SMTP entering state: 16
[Main Thread]: D/SMTP SMTP AuthLoginStep1() for [hidden email]
[Main Thread]: D/SMTP PLAIN auth
[Main Thread]: I/SMTP Logging suppressed for this command (it probably
contained authentication information)
[Main Thread]: I/SMTP SMTP entering state: 0
[Main Thread]: I/SMTP SMTP Response: 235 2.7.0 Logged in.
[Main Thread]: I/SMTP SMTP entering state: 18
[Main Thread]: D/SMTP SMTP Login response, code 235
[Main Thread]: I/SMTP SMTP entering state: 3
[Main Thread]: I/SMTP SMTP Send: MAIL FROM:<[hidden email]>
BODY=8BITMIME SIZE=425

[Main Thread]: I/SMTP SMTP entering state: 0
[Main Thread]: I/SMTP SMTP Response: 555 5.5.4 Unsupported mail BODY type
[Main Thread]: I/SMTP SMTP entering state: 5
[Main Thread]: I/SMTP SMTP Send: QUIT

[Main Thread]: I/SMTP SMTP entering state: 0
[Main Thread]: I/SMTP SMTP entering state: 0
[Main Thread]: I/SMTP SMTP Response: 221 2.0.0 Bye
[Main Thread]: I/SMTP SMTP entering state: 11
[Main Thread]: I/SMTP SMTP entering state: 12
[Main Thread]: I/SMTP SMTP connection error quitting 80004004, ignoring

> (ngrep -Wbyline produces more readable output)

Thanks.  ngrep seems to hate IPv6 though, but after a bit of forcing
IPv4 it started working (the output was the same as the tcpdump).

> I will continue experimenting a bit. I still have to actually try this
> with Thunderbird. Any other configuration I should know about (`dovecot
> -n`)?
I think that'd help.  I'm using Thunderbird on Windows.

This thread might be of interest:

http://forums.mozillazine.org/viewtopic.php?f=39&t=2849171
https://bugzilla.mozilla.org/show_bug.cgi?id=1032302

It all seems to suggest that this could be a client side specific bit of
quirkiness that dovecot submission is not handling.

Config is up here:

http://www.reub.net/files/dovecot/thunderstorm-dovecot.conf

Thanks,
Reuben

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Re: dovecot-submission SMTP send error with Thunderbird (BODY=8BITMIME)

Stephan Bosch-2
Op 12/24/2017 om 7:54 AM schreef Reuben Farrelly:

> Hi again,
>
> On 24/12/2017 7:11 am, Stephan Bosch wrote:
>> Op 12/23/2017 om 7:18 AM schreef Reuben Farrelly:
>>> Hi,
>>>
>>> With latest 2.3 -git (and 2.3.0 release), I'm running into this error
>>> with Thunderbird:
>>>
>>> "An error occurred while sending mail. The mail server responded:
>>> 5.5.4 Unsupported mail BODY type. Please verify that your email
>>> address is correct in your account settings and try again."
>>>
>>> This is fatal and means Thunderbird cannot use the submission service
>>> - fortunately I can revert back to a native Postfix service which
>>> works.
>>>
>>> Here's a tcpdump of the conversation:
>>>
>>> thunderstorm /etc/dovecot/conf.d # tcpdump -A port 587
>>>
>>> dropped privs to tcpdump
>>> tcpdump: verbose output suppressed, use -v or -vv for full protocol
>>> decode
>>> listening on eth0, link-type EN10MB (Ethernet), capture size 262144
>>> bytes
>>
>> I cannot reproduce this behavior so far.
>
>> I will continue experimenting a bit. I still have to actually try this
>> with Thunderbird. Any other configuration I should know about (`dovecot
>> -n`)?

Fix pending:

https://github.com/stephanbosch/dovecot-core/commits/fix-submission-thunderbird

Regards,

Stephan.
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Re: dovecot-submission SMTP send error with Thunderbird (BODY=8BITMIME)

Stephan Bosch-2
Op 12/27/2017 om 3:28 PM schreef Stephan Bosch:

> Op 12/24/2017 om 7:54 AM schreef Reuben Farrelly:
>> Hi again,
>>
>> On 24/12/2017 7:11 am, Stephan Bosch wrote:
>>> Op 12/23/2017 om 7:18 AM schreef Reuben Farrelly:
>>>> Hi,
>>>>
>>>> With latest 2.3 -git (and 2.3.0 release), I'm running into this error
>>>> with Thunderbird:
>>>>
>>>> "An error occurred while sending mail. The mail server responded:
>>>> 5.5.4 Unsupported mail BODY type. Please verify that your email
>>>> address is correct in your account settings and try again."
>>>>
>>>> This is fatal and means Thunderbird cannot use the submission service
>>>> - fortunately I can revert back to a native Postfix service which
>>>> works.
>>>>
>>>> Here's a tcpdump of the conversation:
>>>>
>>>> thunderstorm /etc/dovecot/conf.d # tcpdump -A port 587
>>>>
>>>> dropped privs to tcpdump
>>>> tcpdump: verbose output suppressed, use -v or -vv for full protocol
>>>> decode
>>>> listening on eth0, link-type EN10MB (Ethernet), capture size 262144
>>>> bytes
>>> I cannot reproduce this behavior so far.
>>> I will continue experimenting a bit. I still have to actually try this
>>> with Thunderbird. Any other configuration I should know about (`dovecot
>>> -n`)?
> Fix pending:
>
> https://github.com/stephanbosch/dovecot-core/commits/fix-submission-thunderbird

 Merged (9 commits):

https://github.com/dovecot/core/commit/d63fbcb367b6de01f5e39d72a825f03a832e308f

Regards,

Stephan.