CiviMAIL (management of mailing lists and newsletters) allows to:

• send mailing to specific groups of contacts (include / exclude)
• reuse already sent mailing
• automatic management of unsubscribe / opt-out
• highlight unreachable email addresses (bounce) and the reason why
• track for each recipient opening, re-opening and forwarding of your mailing
• track for each recipient specific clickthroughs
• set variable fields (tokens) within your mailing
• use default headers/footers