A new POP3 server has been deployed. It was rewritten from the ground up in Golang. The source code will be released to GitHub soon.
The original Node.js POP3 server consumed far more memory than we felt necessary (120 MB upon startup, 400 MB under regular load), and the codebase relied on some packages which were outdated due to the author re-licensing dependencies under restrictive licenses, and removing some of the source code from GitHub. We had to pin to older versions which were initially published under the MIT license. There are still other Mailsac SMTP services packages stuck on older SMTP packages; these will be migrated to Go soon also. We hope to open source as much as possible again soon – the Mailsac GitHub project is far out of date from mailsac.com.
Mailsac POP3 settings