What is the message size limit with Paubox?

There is a 150MB size limit for each email sent with any Paubox Email Suite plan. If you send an attachment larger than 150MB, it will bounce back to you as an undeliverable message.

Paubox maximum message size limit is 150 MB for both inbound & outbound. For Paubox customers hosted by Microsoft 365, transcoding may occur and increase the file size by 33%, sending 100 MB or lower is recommended.

Note: Google Workspace and Microsoft 365 may enforce lower attachment size limits than Paubox.