delivterms
DELIVTERMS: The weekly series here on Spam Resource that defines deliverability terminology. Today, I’m going to talk about HELO/EHLO.When you send me an email from your account on Outlook.com to my account at Gmail.com, Outlook builds the email message based on your content, then its outbound mail server connects to and transmits that message to an inbound mail server at Gmail. Those servers communicate with each other using a protocol called Simple Mail Transfer Protocol (SMTP).When one server connects to another, the receiving server offers up a bit of text upon connect, called an SMTP banner. The sending server responds with a HELO (Hello) or EHLO (Extended Hello) command, basically saying “Hi, I am a mail server and my name is XYZ.”I don’t want to go too far into the weeds and turn this post into a whole breakdown of how SMTP works. Instead, let me focus on where the…
DELIVTERMS: The Monday series here on Spam Resource that defines deliverability terminology. Today, I’m going to talk about VERP: Variable Envelope Return Path.VERP (Variable Envelope Return Path) is where you encode the return-path address (remember that from last week) on a per-recipient basis, uniquely changing it for each recipient. If somebody sends an email to two people, you and me, your copy of the email message will have a return-path header with a one code in it, and my return-path header will have a different code in it. (You can find examples over on the VERP Wikpedia page.)Why? VERP helps email sending platforms (ESPs, CRMs, etc.) more easily track which email messages weren’t delivered — which ones bounced back to the sender.To understand how VERP helps with bounce tracking, we need to understand how bounces are communicated between senders and receivers. There are basically two ways bounces can be communicated…