I'm setting up an alternative submission relay host for dovecot. Atm, it's
pointing @ fastmail.com.
with dovecot config,
submission_relay_host = smtp.fastmail.com
submission_relay_port = 465
submission_relay_ssl = smtps
submission_relay_ssl_verify = no
submission_relay_trusted = yes
submission_relay_user = 'acc...@mydomain.com'
submission_relay_password = 'acctPWD'
submission relay via dovecot proxy works as expected -- mail's
delivered/received by intended recipient.
in local dovecot logs I notice
==> /var/log/dovecot/dovecot.log <==
2020-09-24 16:22:19
submission(recipi...@example.com)<xxxxxxxxxxxxxxxx>: Warning: smtp-client: conn
smtp.fastmail.com:465 (66.111.4.140:465) [1]: Received invalid EHLO response
line: Unexpected character in EHLO keyword
at debug level
==> /var/log/dovecot/dovecot-debug.log <==
2020-09-24 16:22:19
submission(recipi...@example.com)<xxxxxxxxxxxxxxxx>: Debug: smtp-client: conn
smtp.fastmail.com:465 (66.111.4.140:465) [1]: command EHLO: Got reply (1/1):
250 mail.messagingengine.com PIPELINING SIZE 73000000 AUTH DIGEST-MD5 CRAM-MD5
NTLM LOGIN PLAIN AUTH=DIGEST-MD5 CRAM-MD5 NTLM LOGIN PLAIN ENHANCEDSTATUSCODES
8BITMIME (1 commands pending, 0 commands queued)
it's clearly non-fatal, simply a warning.
i certainly do _not_ see this with every relay host, so suspect it's unique to
fastmail's EHLO response. at least within the set of hosts I've tested.
i'd like to find/fix it ... either at my dovecot instance, or @ fastmail.
what's specifically invalid about
250 mail.messagingengine.com PIPELINING SIZE 73000000 AUTH DIGEST-MD5
CRAM-MD5 NTLM LOGIN PLAIN AUTH=DIGEST-MD5 CRAM-MD5 NTLM LOGIN PLAIN
ENHANCEDSTATUSCODES 8BITMIME
by dovecot's 'measure'?
