Hi, We had a Mimecast user report today that their mail was being rejected with a 4.7.0 "too many connections" error. This is a "soft" error, in that the mail client will later attempt to resend, correct?
Isn't the default of 50 concurrent connections sufficient for most environments? Is there really any reason I should consider increasing that limit? Isn't it a bit much for them to expect to be able to make 50 separate connections in the first place? Maybe those are subjective questions, but I'm interested in what people normally do. Here are a few of the logs from both postscreen and smtpd. Dec 13 17:01:18 mail03 postfix/postscreen[15590]: NOQUEUE: reject: CONNECT from [216.205.24.100]:33254: too many connections Dec 13 17:01:18 mail03 postfix/postscreen[15590]: DISCONNECT [216.205.24.100]:33254 Dec 13 17:01:18 mail03 postfix/smtpd[27153]: connect from us-smtp-delivery-100.mimecast.com[216.205.24.100] Dec 13 17:01:18 mail03 postfix/smtpd[27141]: connect from us-smtp-delivery-100.mimecast.com[216.205.24.100] Dec 13 17:01:18 mail03 postfix/smtpd[27153]: warning: Connection concurrency limit exceeded: 5 from us-smtp-delivery-100.mimecast.com[2 16.205.24.100] for service smtpd Dec 13 17:01:18 mail03 postfix/smtpd[27141]: warning: Connection concurrency limit exceeded: 6 from us-smtp-delivery-100.mimecast.com[2 16.205.24.100] for service smtpd Are there other parameters I should consider? This is with postfix-3.3.1. postconf -d|grep smtpd_client_connection_count_limit postscreen_client_connection_count_limit = $smtpd_client_connection_count_limit smtpd_client_connection_count_limit = 50 Thanks, Alex
