Pegasus Mail & Mercury

Welcome to the Community for Pegasus Mail and
The Mercury Mail Transport System, the Internet's longest-serving PC e-mail system!
Welcome to Pegasus Mail & Mercury Sign in | Join | Help
in
Home Blogs Forums Downloads Pegasus Mail Overview Mercury Overview Wiki

When is the SMTP envelope created?

Last post 07-09-2015, 15:53 by Greenman. 2 replies.
Sort Posts: Previous Next
  •  07-07-2015, 16:58

    • Greenman is not online. Last active: 21 Nov 2019, 9:28 Greenman
    • Top 10 Contributor
    • Joined on 07-19-2007
    • UK
    • SuperStar
    • Points 14,300

    When is the SMTP envelope created?

    I'm a little confused (what's new ;) ), about when the SMTP envelope is created and part of the SMTP delivery process. I have seen many references to the envelope but nothing tangible about its creation. Can anyone offer some clarification please?

    In our setup Pegasus Mail creates the message and delivers it to Mercury. Mercury accepts it and creates a .101 file (or does Pegasus Mail create the .101 file?), Mercury then converts the .101 into the job queue pair and then opens those to determine where the message needs to go.

    It then connects (using MercuryC), to the cloud filtering service we use which then 'filters' the message. This is where I am a little unsure about the delivery process.

    Does the filtering service establish the connection to the receiving server after it has checked the message so that the EHLO etc command/response process can begin or does the filtering service tell Mercury to establish the connection once the message is considered safe for transmission?

    Is the envelope created when Mercury hands the message over to the filtering service? If so, does Mercury create the envelope?

    Thanks :)

  •  07-09-2015, 15:22

    • PaulW is not online. Last active: 13 Dec 2019, 16:00 PaulW
    • Top 10 Contributor
    • Joined on 05-08-2007
    • UK
    • SuperStar
    • Points 18,410

    Re: When is the SMTP envelope created?

    Greenman:

    I'm a little confused (what's new ;) ), about when the SMTP envelope is created and part of the SMTP delivery process. I have seen many references to the envelope but nothing tangible about its creation. Can anyone offer some clarification please?

    The envelope is a name given to the addressing part of the email message consisting of the "MAIL FROM" and "RCPT TO" SMTP commands.  It doesn't always exist as a separate identifiable part of the message, although there are usually traces of it in residual headers in the delivered message.

    In our setup Pegasus Mail creates the message and delivers it to Mercury. Mercury accepts it and creates a .101 file (or does Pegasus Mail create the .101 file?),

    PMail creates the .101 file with a $$ line containing the originating address and (possibly multiple) T, C, and B lines for the destination, CC and BCC addresses.  These lines are effectively the envelope.

    Mercury then converts the .101 into the job queue pair and then opens those to determine where the message needs to go.

    It then connects (using MercuryC), to the cloud filtering service we use which then 'filters' the message. This is where I am a little unsure about the delivery process.

    Does the filtering service establish the connection to the receiving server after it has checked the message so that the EHLO etc command/response process can begin or does the filtering service tell Mercury to establish the connection once the message is considered safe for transmission?

    This depends on the filtering service - for instance I see Messagelabs take the message and then deliver it.  You should be able to tell by looking at the headers of a message that has been sent.

    Is the envelope created when Mercury hands the message over to the filtering service? If so, does Mercury create the envelope?

    Usually it will exist before the message gets to Mercury - as in your example.  If the message is an error notification or a delivery report generated by Mercury, then it will have created everything.

  •  07-09-2015, 15:53

    • Greenman is not online. Last active: 21 Nov 2019, 9:28 Greenman
    • Top 10 Contributor
    • Joined on 07-19-2007
    • UK
    • SuperStar
    • Points 14,300

    Re: When is the SMTP envelope created?

    That's cleared up several things for me. Thanks very much PaulW!

    Yes

View as RSS news feed in XML

Contact | Advertise | Host provider: PraktIT | Terms of Use | Privacy Statement
Copyright © 2007-2011 David Harris / Peter Strömblad. | Pegasus Mail Home Page