FYI (I haven't seen this in ports yet): If sendmail tried to reuse an SMTP session which had already been closed by the server, then the connection cache could have invalid information about the session. One possible consequence was that STARTTLS was not used even if offered. The problem can be fixed by either: - applying the patch (for 8.15.2) available at ftp://ftp.sendmail.org/pub/sendmail/8.15.2.mci.p0 ftp://ftp.sendmail.org/pub/sendmail/8.15.2.mci.p0.sig - or disabling the connection cache: define(`confMCI_CACHE_SIZE', `0')
The problem can be mitigated by setting at least one of these options: - using a very short timeout: define(`confMCI_CACHE_TIMEOUT', `5s') - sorting the queue by hosts: define(`confQUEUE_SORT_ORDER', `Host') Note: This issue is fixed in sendmail snapshot 8.16.0.16 (or newer) for those who would like to test upcoming releases.
