Hi all,

we are using dovecot since several years without any problems or trouble.

Now we are having trouble with a few of our customers - they are trying to fetch their emails every few seconds (3-5!). These customers are using Microsoft Exchange Server and also all of these customers are cared by the same IT Professional...

Is it possible to send a pop3 "LOGIN-DELAY" if the customers last login is only a few seconds away? A simple firewall rule for rate limiting is not possible because most of them are business customers and they are connected using NAT.

In RFC2449 <https://www.iana.org/assignments/pop3-extension-mechanism/pop3-extension-mechanism.xhtml> I read that the pop3 capability "LOGIN-DELAY" exists. But it seems that dovecot does not offer this? Why?

Kind regards

Markus