Am 24.05.2019 um 16:23 schrieb Brent Clark: Hi Brent, option 1: This option should be chosen if you can not tell which domains are valid and which are not. Use regular expression maps. Maybe you have a look at: https://de.slideshare.net/jpmens/the-perdition-and-nginx-imap-proxies especially slides 11 and 13, last line on slide 13 is very close to what you want to achive. You would need something like ^(.*)$: $1:993 Note that you should definitely have some outgoing network filter, because otherwise you are building an open IMAP relay for everyone with this configuration. option 2: If you have a data source that contains a list of valid domains, preferably LDAP or database, you should use the corresponding map modules from perdition. If it is some other kind of data source, maybe write a small script that reads the domain list regularly and generates the popmap. This way the perdition instance cannot be abused to connect somewhere else. for BOTH options you need to set the option "query_key" to "\d" so that only the domain part of the incoming user name is used as lookup key. Regards Matthias