remove pop3 service from basic service in mail plugin

Descriptive title for this enhancement

remove pop3 service from basic service in mail plugin

Actual behavior

basic service talk about imap/pop3, pop3 is no longer used and should be removed

Expected behavior

only see basic imap service on the basic service in the mail plugin

changed milestone to %FusionDirectory 1.4

added PJ1802-0188 enhancement plugin-mail labels

closed via commit 436d6d3f

added Removed label

removed enhancement label

added 10m of time spent at 2021-01-28