When you send a mailing, there is a chance that for some recipients, your message will not arrive. In the world of email, we call this 'bounces'. We distinguish between soft bounces and hard bounces.
MailPro attempts to deliver your email to the recipient’s mail server. In most cases, a bounce is returned immediately by the receiving server. However, this is not always the case. Sometimes it can take time before a definitive response (success or failure) is received. MailPro will continue trying to deliver the email for up to 4.5 days. If delivery is still not possible after this period, this is also interpreted as a bounce.
Based on the status code and bounce message returned by the receiving server, MailPro determines whether a bounce is classified as a soft bounce or a hard bounce.
Soft bounces
A soft bounce usually indicates a temporary problem in delivering your message. For example, because your recipient’s mailbox is full, because the mail server is temporarily unavailable, or because the message is too large.
In this case, a subscriber first ends up in the Soft bounce (1x) group. If the next consecutive sendout bounces again, in the Soft bounce (2x) group and finally in the Soft bounce (def) group. If a subsequent mailing was delivered successfully, the "consecutive bounce counter" resets.
Hard bounces
A hard bounce means there is a permanent reason as to why a message cannot be delivered. Possible reasons include: the recipient’s email address doesn’t exist (anymore), the domain name doesn’t exist or the recipient’s mail server blocks all forms of traffic (from your server) (spam block).
If one of your emails shows a hard bounce, it will follow the same process as with Soft Bounces through the (1x), (2x) and (def) group. However, in case of a hard bounce during the very first mailing within a campaign, the subscriber will immediately be sent to the Hard bounce (def) group, without any in-between stops in (1x) or (2x). When a contact Hard Bounces, the contact will also be added to the Exclude List if that is enabled in the campaign.
Lowering your bounce rates
To lower the bounce rates, first and foremost, domain alignment is important. Ensure your domain uses the necessary DNS entries such as DKIM, DMARC and SPF.
Also, keep your database is healthy. There is a set of measures that can be taken, for example email validation, form protection and the most important: using a double opt-in.
Another important factor is sender reputation. You can maintain this by sending relevant content at the right moment to the right people.