Docs / Connect / Mail
Mail is the most private text on your computer, so ModelBrain reads it where it sits and never offers it to a hosted app. The mail source reads mbox files and indexes each message as its own memory in a partition called Email. A mailbox of several gigabytes is never read whole. Available from ModelBrain 0.6.6.
From a terminal, connector_sync register <id> <path> --type mail does the same. For example: connector_sync register mail ~/Mail/export --type mail.
mbox, or ending in .mbox or .mbx, which covers Apple Mail bundles. Also extensionless Thunderbird folder files that have a .msf file beside them. Both mboxo and mboxrd styles work.Message-ID. A message without one is keyed by a hash of its date, sender and subject..mbox on the end.A container file over 4 GiB is refused and recorded as a failure, not dropped. Set MODELBRAIN_CONTAINER_MAX_BYTES to change that ceiling. A single member over 32 MiB is refused the same way. ModelBrain finds the messages by streaming each file once and reading only the header of each. It keeps a small index in memory, and when a file has only grown it resumes from the last known message. After ModelBrain restarts, the first pass reads each file through once.
ModelBrain removes a member from memory only after it has read its container to the end. If a file cannot be parsed, every member already indexed from it stays put until the next good pass.
This source is hidden from relay callers. Anything that reaches ModelBrain through the hosted relay, which is how ChatGPT and Grok connect, cannot see what this source imported unless you add its partition (and the partition of any other source of the same kind) to that connection's allowlist yourself. This is the default for every mail source.
kind, members, members_failed and last_container_bytes.The file could not be read, or it is over the container cap. Messages already indexed from it are kept until a pass reads it to the end.
It may be named Spam, Junk, Trash, Deleted or Bin. Rename it if you want it indexed.
The folder file needs its .msf summary beside it, and the file must have no extension.
Open the ModelBrain menu, choose Vaults, then Add Source, then Mail (mbox files), and pick a folder of mbox files. Available from ModelBrain 0.6.6.
mbox files in mboxo and mboxrd style, Apple Mail .mbox bundles, and Thunderbird folder files that have a .msf file beside them.
No. The Email partition is hidden from relay callers, which is how ChatGPT and Grok connect. Local clients on your own computer can read it.
No. Attachments are listed by name and their contents are never read. Spam, Junk, Trash and Deleted folders are skipped.
Each new source kind has its own page.
Claude Code memory → · ChatGPT export → · Calendar and contacts → · Bookmarks →Sources feed the same memory these assistants read.
Claude Desktop → · Claude Code → · Cursor →