Hi,all
I have a POP3 problem about multi users from one IP address concurrent.
[Issue description] The network architecture is as following. I have setup a mail server(sendmail/dovecot) in PlaceA with IP_A. And about 6 users are receving mail from the same IP_B( NATed public IP) in PlaceB. Their mails are many( about 1Mb/hour each) and ususally set fetch time as 10min/fetch.
Then they complain that their mails often cannot be downloaded.
[Reason investigation] I noticed that 1.when one of them fail to fetch mail. All TCP IP connection between IP_A and IP_B will be RST.which means that http/ssh/pop/smtp all not work for a while. And after about 10 minute, the http/ssh can work well. 2.I have asked them to backup and delete pop accounts and use webmail through imap provided by dovecot.And that seems work well but inefficient.
I think this maybe because of multi users from one IP address concurrent,
[Question] Would you pls provide some suggestion or solution about this issue? Is this a bug of dovecot or just a mis-configuration I don`t know?
Thanks in advance for any advice.
Best regards, Yi Xuan