Is there some Indy best practice to avoid to generate email marked as spam?

Question

This question is the non spam bible.

Anyway in addition to that when generating programmatically emails with Indy which are the best practices to follow to minimize the possiiblity of being marked as SPAM?

Answer 1

In general, I would say:

• Fewer recipients (more emails, if necessary)
• Avoid symbols in the subject
• Avoid excessive symbols and spelling mistakes in the body
• Keep all HTML properly formatted with end tags and proper headings
• Avoid profanity and questionable phrases
• Make sure all required email headers are filled in correctly (including "Content-Type", "Precedence", "From", and "Reply-To")

That's just the general stuff off the top of my head.

EDIT: A good reference for parts of an email: http://en.wikipedia.org/wiki/Email

Answer 2

In addition to Jerry's comments about what you can do about the mail, there are also things that can be done to the way to deliver.

• If you go to your ISPs SMTP server, try to find an authenticated way to deliver mail
• If you deliver to other SMTPS
  • make sure that you have a decent reverse DNS mapping for the sending machine, preferably with something with SMTP in it.
  • react to HELOs, iow run a SMTP server that accepts mail for the sending address.

Answer 3

On ancient versions of the Indy library, it was setting the X-Library header which was a flag for spam so one Indy-specific suggestion is to ensure to use the latest versions of Indy.