rado wrote:
hi Y'all,
Oh, I am guilty of running programs that I don't know exactly what
they/their job is in the total process.
I'm talking about the mail system I have set up.
I just have a basic sendmail/procmail/evolution pop setup.
I want to know exactly what sendmail's job is. The man sendmail page
says it's job is to sendmail, as the name implies. Please tell me if my
thinking is warped. I think sendmail sends the mail in both directions.
you write a msg, it goes to sendmail and it gets sent on the way. a msg comes in sendmail is listening on, think it's port 25. sendmail
grabs it and.....
Sendmail sends mail & receives mail on port 25, as you have said. It also handles delivery of mail (i.e. puts new mail in /var/spool/user)
Here is where I am hung up. What actually takes place now? In just a basic, Sendmail system w/out many changes at all that came
stock w/FC3, can I assume that: Say a msg comes in for rado, does it go
to var/spool/mail/rado?
yes
when exactly does procmail get in the game?procmail is for setting filters
I notice that in /home/rado there is lots of stuff concering mail.
i.e. setup a filter so all mail which is addressed to fedora-list@xxxxxxxxxx gets put into a different folder/file
~/Mail, ~/mail, ~/.evolution.. folders in your home dir, are hidden folders, and usually used for user settings
I really don't want to get too, too, tech here, just a little understanding of where the mail trail goes and how to follow it.
You send mail ...
you type your mail etc, and if your smtp server is set to localhost ... then it connects to sendmail server, tells it who mail is from, who it is for, and then if their accepted, gives the message subject/body.
sendmail, if all is correct etc, will then lookup the MX record for the domain your sending to (i.e. if your sending mail to user@xxxxxxxxxxx, it looks up the MX record for example.com (nslookup/dig)) and connects to that address on port 25, telling the remote server who it has mail for, and who it's from etc.
the RFC on SMTP is quite handy to read, not too bad a read.
Regards,
Sean
