Why do MKV attachments bounce more mysteriously than MP4?
Matroska happily carries HEVC video, FLAC commentary, PGS bitmap subs, chapters, and attachments in one polite filename—SMTP scanners see complexity and peak bitrate spikes, not just megabytes in Finder. Searchers type mkv too large email, outlook attachment limit, remux compress, softsub mkv size, and remove extra audio track because the fight is gateway math plus policy, not container religion. Rational email strategy trims width and peak bitrate, flattens optional commentary stems when contracts allow, and keeps twenty-plus percent headroom under the nominal cap for Base64 and antivirus duplication. Burning subtitles for review locks pixels forever—prefer softsubs or sidecars when recipients can handle them. Season-long remuxes belong on object storage links with checksum manifests, not inside threadbare SMTP pipes. Sensitive dashboards do not redact themselves when files shrink. Ai2Done keeps the email variant procedural: inventory streams, export gateway probes on the same tenant class, log hashes, and never overwrite the only remux masters legal still calls original.
How to compress MKV for Outlook-class delivery
- Open Compress MKV, pick the email variant, read codecs, HDR flags, audio and subtitle maps, then read max size and duration caps before uploading multi-hour captures.
- Choose which dialogue stem and subtitle mode survive the attachment pass, lower width and peak bitrate with mail presets, and send a probe through the same gateway class to measure scan time.
- Document default audio language, codec, resolution, and review-only intent in the email body, link untouched masters with checksums on approved storage, and forbid attachment-only custody of the sole remux.