jcoffey-dev is traveling from Thursday 1 October through Sunday 4 October. Issues and pull requests are welcome, and will get an answer after that. Thanks for your patience.
Two things let a large mailbox fill memory. IMAP workers handed every
fetched message to the archive writer through an unbounded queue, so fast
workers could hold whole folders' worth of bodies while the single writer
caught up. And fetch batches were sized by count only: 20 items per EWS
GetItem, 8 connections at a time, is a few megabytes of ordinary mail and
several gigabytes of large attachments.
- The IMAP event queue is bounded at two events per worker, so a worker
waits for the writer instead of running ahead of it.
- Fetch batches are bounded by bytes as well as by count, with a shared
helper, `sync::batch::by_count_and_bytes`: 32 MiB by default, and a
single larger message goes alone.
- IMAP learns each new message's RFC822.SIZE on the control connection,
in 1000-UID metadata fetches, before the body fetch. A server that won't
say leaves the chunks sized by count. `--fetch-batch-mib` sets the cap.
- EWS asks FindItem for `item:Size` and packs GetItem batches by it,
fetched `--ews-connections` batches at a time. `--ews-getitem-batch-mib`
sets the cap. Items from an incremental SyncFolderItems run carry no
size and stay batched by count.
- docs/usage.md describes both options.
The crate, binary, library path and every name the tool writes or reads
become inbuxa-migrate: the CLI name and about text, the HTTP user agent,
the credential variables (INBUXA_MIGRATE_PASSWORD, _TOKEN,
_EWS_CLIENT_SECRET and _GRAPH_TOKEN, with no fallback to the old names),
thread names, synthesized UIDs and calendar addresses
(urn:x-inbuxa-migrate:attendee:), and the Maildir file suffix used by the
export script. This is a new tool, so archives written by Vandelay are not
read back.
The version moves to the date scheme the release tags use (2026.9.30), and
the package metadata points at the inbuxa-migrate repository. The cargo-dist
and MSI metadata goes with the release tooling it served.
Modified files carry an added copyright line; the original notices stay.