On 01/30/2018 06:44 PM, Tech Gurus wrote:
Just checking back if there is recommendation to increase outbound mail delivery .
Can you characterize the distribution of your mail delivery? In other words, if you take each mailpiece, determine the MX, and collate the results, do you have a lot of mail going to relatively few endpoints, or do you have a wide spread of targets?
What is the nature of the emails themselves? Are they small messages, or are they carriers of huge attachments? Some mail exchangers will throttle large volumes of mail from a single IP address. Large as in count, or large as in size, or some combination.
Do you throttle your sending in any way to major mailers like Yahoo and Google? I know that, in order to get mail to the "free" mail servers, I had to eliminate any concurrent sendings to avoid triggering their anti-spam measures. That means you will need a large hard disk (although "large" a decade a go is bordering on entry size today) to hold the mail spool.
Do you have people doing mass mailing? If so, you need to segregate those potential abusers onto a separate mail exchanger. In my prior practice, I set up individual MX systems for customers who do large mass mailings; for example, a real-estate clearinghouse sent house listings to agents all over the place. One huge newsletter operator needed her own mail exchanger, too.
Have you examined the subject lines of the mail going out from your system? Have you put in any protective messages so that any spam mail is tossed before it enters your mail queue? On my systems, I maintained a header_checks file with all the common spam subjects. (It helps that I had a small collection of honeypot mail addresses so I could harvest those spam subjects.)
Finally, what measures have you taken to avoid outsiders injecting mail? If you are a Web host, for example, have you hardened all the mail-out Web pages against various forms of injection? Do you accept mail only from your users, or are you running an open mail relay?
Before you try to come up with a solution, you need to find out the parameters of your problem.
