@gronke: Some email mailboxes can have additional aliases/identities/sender emails, e.g. info@example.com may be the primary email address, but it also has contact@other-domain.tld as additional email address which email is delivered to info@example.com and which can also be used as a sender email address.
Without auto-configuration those additional email addresses have to be set up by the user manually.
@gronke: Some email mailboxes can have additional aliases/identities/sender emails, e.g.
info@example.commay be the primary email address, but it also hascontact@other-domain.tldas additional email address which email is delivered toinfo@example.comand which can also be used as a sender email address.Without auto-configuration those additional email addresses have to be set up by the user manually.