- 421 DYN:T1
http://postmaster.info.aol.com/errors/421dynt1.html
EXPLANATION AND SOLUTION:
If you are getting DYN:T1 blocks and you do not send bulk mail, marketing, or advertisements via this IP, please open a support request.Please include the IP, what kind of mail you send, and mention that you are getting DYN:T1 errors.
Please be as accurate as possible about the type of mail you send so that we can accurately evaluate your mail stream.
If you do send bulk mail, marketing, or advertisements then your IPs are receiving temporary email failures due to reputation issues or a lack of whitelisting.
If you are a bulkmailer and have not previously applied for whitelisting: once you have a good 30 day (minimum) mailing history built, we recommend applying for whitelisting.
If you are already whitelisted it is important to note that whitelisting protects your IP from many of AOL's filters, but is not a guarantee of delivery. Whitelisting does not affect the routing of email to users' inboxes. Mail from whitelisted IPs can be delivered to either the inbox or the spam folder, or tempfailed (421:DYNT1) if the sending IP's reputation is poor or not yet established. The best way to improve your inbox delivery at AOL is to establish a good IP reputation.
We are still delivering a portion of your mail, and we will recalculate your reputation based on the performance of that mail. If the cause is reputation-related, the failures will cease as your IP reputation improves. For best deliverability, be sure you are following AOL's Best Practices.
