MTA Timeout exceeded

[neiren]

The customer turned on MTA and threat simulation, and after a few days of use, there was a long email timeout every day

We found the following problems through observation:

1. When there is a large number of mass mailings, there will be mail timeouts, and most of the timeout mails are group mails.

2. If there is no mass mailing, it is normal to receive mails

3. We checked and found that the threat simulation will simulate all the emails in the group email, which we think is unreasonable.

[PhoneBoy]

Is this the Harmony Email and Office product (where you posted this) is this Threat Emulation on a Check Point appliance?
If the latter, please provide version/JHF and a diagram.
Are these outbound emails you are trying to send or inbound ones?
In either case, it seems like these bulk emails should be excluded from scanning, since I assume they are coming from a known, trusted source.