Simple Mail Transfer Protocol (SMTP)
This protocol is widely use to send e-Mail from the authors mail program to the mail server and between servers too.
Receiving mail from a server - on the other hand - is done using POP or IMAP.
SMTP is existing since the early days of the internet and was one of the first protocols used.
TCP: Typically, SMTP uses TCP as its transport protocol. The well known TCP port for SMTP traffic is 25.
SMTP uses MIME_multipart to transfer attachments
XXX - Add example traffic here (as plain text or Wireshark screenshot).
The SMTP dissector is fully functional.
(XXX add links to preference settings affecting how SMTP is dissected).
Example capture file
XXX - Add a simple example capture file to the SampleCaptures page and link from here. Keep it short, it's also a good idea to gzip it to make it even smaller, as Wireshark can open gzipped files automatically.
A complete list of SMTP display filter fields can be found in the display filter reference
Show only the SMTP based traffic:
Show only the SMTP based traffic with the "MAIL FROM" command:
smtp.req.parameter contains "FROM"
You cannot directly filter SMTP protocols while capturing. However, if you know the TCP port used (see above), you can filter on that one.
RFC821 SIMPLE MAIL TRANSFER PROTOCOL
RFC822 STANDARD FOR THE FORMAT OF ARPA INTERNET TEXT MESSAGES
RFC2821 Simple Mail Transfer Protocol (updates and clarification)
Imported from https://wiki.wireshark.org/SMTP on 2020-08-11 23:25:44 UTC