Mail concepts.
IMAP
Keeps mail on the server, synchronised across devices.
POP
Downloads mail to one device, usually removing it from the server.
SMTP
The protocol for sending mail.
WEBMAIL
Access to mail through a browser.
MAILBOX
An email account with its own storage.
ALIAS OR FORWARDER
An address delivering to another mailbox, with no storage of its own.
AUTORESPONDER
An automatic reply sent to incoming mail.
MX RECORD
The DNS record directing mail for a domain.
BOUNCE
A message reporting failed delivery.
HARD BOUNCE
Permanent failure. The address does not exist.
SOFT BOUNCE
Temporary failure, such as a full mailbox.
BLACKLIST
A published list of senders associated with spam.
DELIVERABILITY
Whether your mail reaches inboxes rather than spam folders.
