Hi, this is a bug in Outlook really but who would make search on Outlook here :-) As this is a confirmed issue upstreams, which also have a patch for it available, I don't include any emerge info. After upgrading to postfix 2.3.0 it doesn't work anymore to connect from Outlook to send a mail with TLS. The issue is discussed in the attched url pointing to a postfix mail archive. There is also a patch available to fix it, until 2.3.1 is out. A quich fix is to add this to /etc/postfix/main.cf smtpd_tls_session_cache_database = btree:$queue_directory/smtpd_tls_cache /Joakim
upstream fix it with postfix-2.3.2