The first, firstname.lastname@example.org,
does a simple look-up in the OEIS.
Send the message
lookup 1 2 5 14 42 132 429         [no commas!]
for example (with no Subject line).
Up to 30 sequences can be submitted at the same time.
The email reply will tell you any sequences
in the OEIS (up to a limit of 50) that match your sequence.
If the word "lookup" does not appear in your message,
you will be sent the
for this server.
You can also retrieve sequences by A-number -- say
(However, you can't have both sequence lookups and A-number lookups
in the same email message.)