we send mails in bulk from different domains (around 3 domains per day) but now some domain's mails are delivered after 10-15 min and some domain's mails delivered after one or two days and some times mails to gmail or yahoomail either not delivered or delivered simultaneously after two days.
I dont know whats happening. can anyone help me out.
Re: Unexpected behavior of outgoing emails delivery
Can you provide more information from your "mail_logs"?
It seem like you are being "throttled" by the recipents MTA. I know that many ISP's are looking on for instance number of simulatious connections and then start blocking you based on that. If so you can use "destinations control" to make sure you are not opening to many simltaneus connections if needed.
We have configured the outside and inside Interface with official ipv6 adresses, set a default route on outside Interface to our router, we also have definied a rule , which also gets hits, to permit tcp from inside Interface to any6.
In Syslog I also se...