One of the most wide-spread types of abuse is SPAM. We take dealing with abuse seriously, and have since implemented certain safeguards to diminish the issue. To keep our systems healthy, Heficed limits the number of email messages that can be sent from IPs and domains via Port 25.
Currently the limits are as follows:
Base limit is 4500 emails/hour;
Should the algorithm detect any patterns that are indicative of spam or abuse emails, the limit is automatically reduced to 3000/hour;
Emails with a high spam score are limited to 50/8 hours;
Emails with infected attachments are bounced immediately.
Once you reach either of these limits, you can only send new emails as soon as the oldest communication has expired, i.e. time set by the limit has elapsed since the first email was sent. This is to prevent traffic from spiking and equalizing the load.
You will receive a message if you reach the limit, confirming what type of emails these were classified under.
Be advised, that if we observe IP hitting spam limit repeatedly, the range will be block-listed to retain the reputation.
To improve the quality of your messages and mailing practice we suggest you refer to Sender Best Common Practices issued by M3AAWG.
If you have any questions regarding this, do not hesitate to reach out to firstname.lastname@example.org or your assigned account manager.