Question
A remote sender is opening multiple connections to my server and using up all of my SMTP threads.
Answer
You can limit the number of simultaneous connections any remote sender is able to open to your SMTP service by going to the Security > Sessions page in the administration interface and entering a limit for connections.
The POP and IMAP services can also have the number of simultaneous connections limited on this page.
Keywords:SMTP, connections, threads, abuse