What are new delivery controls in PowerMTA?
Email delivery seems to be an easy task but it isn’t. The volume of email and the behavior of receiving systems are two factors that are hard to scale and makes the email delivery bit challenging. But PowerMTA is focused on doing things right. Thanks to the new delivery controls in PowerMTA that makes it an efficient email application.
Now let’s take a look at the new delivery controls in PowerMTA and understand their functioning.
PowerMTA Bounce domains without MX
A mail exchanger (MX) record tells you about the availability of a mail server to receive communication on behalf of recipient domain. Some typos email or domains do exist but they do not accept email. Such domains have an IP but do not publish MX record. If you send emails to such email addresses, it results in bounced emails due to timeout. PowerMTA is built to react differently to such situations. PowerMTA does not immediately bounce domains but does the required looks for short period (one hour or more) before bouncing the emails that do not have MX records.
PowerMTA Change retry intervals
Retrying of messages is done at a fix time interval that is generally 10 minutes. It a mail server will retry 122 times in 24 hours period. With PowerMTA, you can change the intervals. It is a known fact that likelihood of delivery decreases with time. PowerMTA allows you to reduce the number of useless retry attempts by changing the intervals. You can set the retry intervals for first five retries to 5 minutes, 10 minutes, 15 minutes, 30 minutes, and 1 hour.
PowerMTA Bounce on particular 4XX replies
The SMTP replies contain the 4XX code when the recipient’s mailbox is full, the address does not exist, or the account is inactive. As per SMTP standard, the message reply with 4XX code should be retried and these emails remain in the queue until they expire. If the SMTP reply contains 4XX code, the likelihood of message delivery is reduced significantly and retries are wasteful exercises. With PowerMTA, you can create a reply pattern such as mail reply with 4XX code should be bounced instead of retrying.
PowerMTA Limit connections at destination IP
PowerMTA has always been able to limit connections at MX host level and domain level. The new version of PowerMTA features the ability to limit connections at destination IP. Hosting service providers host many domain names with unique MX hostname where each connection resolves to set of IP addresses. If your email management system applies limits per MX or per domain, it can result in errors like – 421… Too many connections… try later. With the ability to limit connections at destination IP, PowerMTA helps in avoiding such errors.
PowerMTA Rollup queues based on MX records
As mentioned earlier, MX records are important in mail delivery system and they are unique to each domain. Mail service providers generally create rollup mail queues based on their domain names. This method is not efficient as domain names move to different providers. Since the mail rollup queues query domain names, there is the possibility of the mail being sent to the wrong MX. Also, the domain lookup is performed in one list only that might not reflect latest changes to the domain name. PowerMTA creates mail rollup queues based on MX records that makes delivery more accurate and efficient.