Mailpopbox has been serving me well for nearly six
years, providing me with disposable but traceable email addresses to give to businesses and mailing
lists. The core workflow is that mailpopbox accepts email over SMTP and makes the resulting messages
available via POP3.
For years, Gmail has had the ability to fetch from remote POP3 accounts. However, in October 2025,
Google announced the deprecation of this feature.
Removing this feature effectively breaks the workflow described above, and so a solution was needed
before the January 2026 removal.
One option I considered was to add forwarding to mailpopbox, where the SMTP server would simply send
the message on to the actual destination mailbox. But forwarding introduces other complexity,
particularly around ARC and DMARC signing.
Instead, I opted to reimplement the Gmail POP3 fetch feature. This new standalone program, called
mailpopbox-router connects to a POP3 server and moves the messages into Gmail using the Gmail
API. One major advantage of this new program is the POP3 poll interval is directly controllable,
whereas the built-in Gmail feature used an indeterminate (and, in my experience, long) polling
interval.
The mailpopbox-router is part of the mailpopbox distribution as of v3, which is released today.
Check out the installation
guide for details.
Currently only POP3→Gmail is supported. But in the future, support for other source and destination
types could be added (e.g. IMAP→IMAP). For now, this solves the acute problem of Google sunsetting
another useful thing.