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

[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.

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 reuben at smtp.reub.net
[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:<reuben at reub.net> 
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