Summary
The Cloud Prefilter service consists of service provider-grade Mail Transfer Agents (MTAs). To protect the servers and to make sure of high availability, there are global security settings in place.
Details
Prefilter MTA global security policies for incoming emails:
- Maximum message size including attachments: 50MB
- Maximum number of recipients: 1000
- Maximum layers of compression for attachments: 19
- Maximum number of files in compressed attachments: 300
Prefilter MTA delivery settings for outgoing emails:
- Delivery retry interval starts from 60 seconds with retry multiplier of 1.5. Therefore, retry interval will increase by half for every delivery attempt. i.e. 60, 90, 135…
- The maximum retry interval is 3600 seconds.
- The maximum time a message stays in the retry queue is 5 days. Before that timeout, the message will be redelivered with retry interval. Afterwards, the message will be removed from the queue and the sender will receive an NDR message.
