ETRN mode does not switch to TLS first
When I use fetchmail with a configuration like:
poll mx.xyz.com with protocol etrn service 587 fetchdomains mydomain wants sslproto "auto";
and the server at mx.xyz.com offers STARTTLS, fetchmail does not start a TLS session:
fetchmail: 6.4.2 querying mx.xyz.com (protocol ETRN) at So 19 Sep 2021 23:25:15 CEST: poll started
Trying to connect to 1.2.3.4/587...connected.
fetchmail: SMTP< 220 mx.xyz.com ESMTP
fetchmail: selecting or re-polling default folder
fetchmail: SMTP> EHLO myhost.domain
fetchmail: SMTP< 250-mx.xyz.com
fetchmail: SMTP< 250-PIPELINING
fetchmail: SMTP< 250-SIZE 128000000
fetchmail: SMTP< 250-ETRN
fetchmail: SMTP< 250-STARTTLS
fetchmail: SMTP< 250-ENHANCEDSTATUSCODES
fetchmail: SMTP< 250-8BITMIME
fetchmail: SMTP< 250-SMTPUTF8
fetchmail: SMTP< 250 CHUNKING
fetchmail: ETRN> ETRN mydomain
fetchmail: ETRN< 530 5.7.0 Must issue a STARTTLS command first
fetchmail: Unknown ETRN error 530
fetchmail: ETRN> QUIT
fetchmail: SMTP< 221 2.0.0 Bye
fetchmail: client/server protocol error while fetching from fetchmail@mx.xyz.com
fetchmail: 6.4.2 querying mx.xyz.com (protocol ETRN) at So 19 Sep 2021 23:25:15 CEST: poll completed
fetchmail: Query status=4 (PROTOCOL)
fetchmail: normal termination, status 4
I can find no way to force a TLS connection, even 'sslproto "TLS1+"' does not work. I could probably use 'ssl', but the server does not offer SSL, only TLS.