#### Email review

SMTP = simple mail transfer protocol
  * port 25
IMAP = Internet mail/message access protocol
  * 993 (secure)
  * 143 (not secure)
SASL = Secure authentication socket layer
  * encrypts stream data (for login)
  * 587, 465
POP3 = Post office protocol
  * 110 (not enc)
  * 995 (secure)
MTA = Mail transport agent (exim, postfix, exchange)
MUA = Mail user agent (thunderbird, roundcube)
MDA = Mail delivery agent (exim)
MBOX = location of message storage

- Look for MX records (A record if it fails)
- `dpkg-reconfigure exim4-config`

Smarthost?
  * Relays mail on behalf of others (stumail)
Satellite?
  * can send, not receive
  * if you respond to (joe@ns1.theg.com) -> mail.theg.com (read on the mailserver)
  * have to configure same name user account on all satellite machines and mailserver

How to dig an MX record?
  * dig @ns1.theg.com ns1.theg.com MX
  * dig @8.8.8.8 fs.theg.com MX