I did notice that a hosting provider uses a single FQDN for multiple hosting servers running IMAP and SMTP. In my mail client I can configure mail.domain.ext as the IMAP and SMTP servers, and use my email address and password to authenticate via ports 993 (IMAP) and 587/465 (SMTPS). The email address and the password are stored on one of the hosting servers which has a different FQDN (eg sv1033.somedomain.ext). I would like to know how this is called and how this works. Edit: I did find this: https://doc.dovecot.org/configuration_manual/forwarding_parameters/ But still need to wrap my head around this matter as it looks to be rather complex. Does anyone have any suggestions? Thanks.