Description
After updating from Mailspring 1.17.1 to 1.17.2, SMTP authentication completely fails while IMAP continues to work. Was able to still send mail from my phone (different mail client) and also tried openssl via terminal which worked fine. Then tried downgrading to 1.17.1, which immediately resolves the issue.
This applies to a mail address which is configured on my VPS (with Postfix + Dovecot) which uses a mail relay by transIP/the VPS host and the domain uses a Let’s Encrypt certificate.
Mailspring Log Shows:
----------IMAP----------
connect mailcore::IMAPSession:001AF4C8
- OK [CAPABILITY IMAP4rev1 LOGIN-REFERRALS ID ENABLE IDLE SASL-IR LITERAL+ AUTH=PLAIN AUTH=LOGIN AUTH=DIGEST-MD5 AUTH=CRAM-MD5] Dovecot ready.
TLS ssl connect mail.svenebens.nl 993 2
OpenSSL version: OpenSSL 3.6.0 1 Oct 2025
connect ok
login
1 LOGIN “info@svenebens.nl” “*********”
1 OK [CAPABILITY IMAP4rev1 SASL-IR LOGIN-REFERRALS ID ENABLE IDLE SORT SORT=DISPLAY THREAD=REFERENCES THREAD=REFS THREAD=ORDEREDSUBJECT MULTIAPPEND URL-PARTIAL CATENATE UNSELECT CHILDREN NAMESPACE UIDPLUS LIST-EXTENDED I18NLEVEL=1 CONDSTORE QRESYNC ESEARCH ESORT SEARCHRES WITHIN CONTEXT=SEARCH LIST-STATUS BINARY MOVE REPLACE SNIPPET=FUZZY PREVIEW=FUZZY PREVIEW SPECIAL-USE STATUS=SIZE SAVEDATE COMPRESS=DEFLATE INPROGRESS NOTIFY LITERAL+ QUOTA] Logged in
2 COMPRESS DEFLATE
2 OK Begin compression (0.001 + 0.000 + 0.001 secs).
3 ENABLE QRESYNC- ENABLED QRESYNC
3 OK Enabled (0.001 + 0.000 secs).
4 NAMESPACE- NAMESPACE ((“INBOX.” “.”)) NIL NIL
4 OK Namespace completed (0.001 + 0.000 secs).
login ok
5 LIST “INBOX.” “*”- LIST (\HasNoChildren \UnMarked) “.” “INBOX.Work: Succesvol Leren”
- LIST (\HasNoChildren \UnMarked) “.” INBOX.TechTown
- LIST (\HasNoChildren \UnMarked) “.” “INBOX.Work planning - Miro”
- LIST (\HasNoChildren \UnMarked) “.” “INBOX.Work - Het Stormt”
- LIST (\HasNoChildren \UnMarked) “.” “INBOX.Work - Caprilli”
- LIST (\HasNoChildren \UnMarked) “.” “INBOX.Work - Aanpoters”
- LIST (\HasNoChildren \UnMarked) “.” INBOX.To-Do
- LIST (\HasChildren \UnMarked) “.” INBOX.Mailspring
- LIST (\HasNoChildren \UnMarked) “.” INBOX.Mailspring.Snoozed
- LIST (\HasNoChildren \UnMarked) “.” INBOX.Archived
- LIST (\HasNoChildren \UnMarked \Trash) “.” INBOX.Trash
- LIST (\HasNoChildren \UnMarked \Sent) “.” INBOX.Sent
- LIST (\HasNoChildren \UnMarked \Drafts) “.” INBOX.Drafts
- LIST (\HasNoChildren \UnMarked \Junk) “.” INBOX.Spam
5 OK List completed (0.002 + 0.000 + 0.001 secs).
6 LIST “” “INBOX”- LIST (\HasChildren) “.” INBOX
6 OK List completed (0.001 + 0.000 secs).----------SMTP----------
connect mail.svenebens.nl 587
220 svenebens.nl ESMTP Postfix
init
EHLO Sven-MiniPC
250-svenebens.nl
250-PIPELINING
250-SIZE 51200000
250-ETRN
250-STARTTLS
250-ENHANCEDSTATUSCODES
250-8BITMIME
250-DSN
250 CHUNKING
start TLS
STARTTLS
220 2.0.0 Ready to start TLS
done
OpenSSL version: OpenSSL 3.6.0 1 Oct 2025
init after starttls
EHLO Sven-MiniPC
250-svenebens.nl
250-PIPELINING
250-SIZE 51200000
250-ETRN
250-AUTH DIGEST-MD5 CRAM-MD5 PLAIN LOGIN
250-ENHANCEDSTATUSCODES
250-8BITMIME
250-DSN
250 CHUNKINGSASL_PATH:
SMTP Last Response Code: 250
SMTP Last Response: svenebens.nl
PIPELINING
SIZE 51200000
ETRN
AUTH DIGEST-MD5 CRAM-MD5 PLAIN LOGIN
ENHANCEDSTATUSCODES
8BITMIME
DSN
CHUNKINGmailsmtp Last Error Code: 296
mailsmtp Last Error Explanation: Unknown
mailsmtp Last Error Location: 10
mailsmtp Last Auth Type: 2
To Reproduce…
Steps to reproduce the behavior:
-
Update to latest 1.17.2 version of mailspring
-
Try to send an email from an existing mail address (running on own domain/vps)
-
Receive warning message the mail can’t be send due to SMTP authentication error
-
Log shows: mailsmtp Last Error Code: 296
mailsmtp Last Error Explanation: Unknown
mailsmtp Last Auth Type: 2
SASL_PATH: [EMPTY]
Expected Behavior
SMPT authenticates and mail is send.
Setup
-
Affected Version: 1.17.2
-
Working Version: 1.17.1
-
Operating System: Windows 11
-
sasl_mechanisms_affected: [PLAIN, LOGIN]
-
Mail Server: Postfix + Dovecot (Plesk) with TransIP relay