Compress video for email
Gmail attachments cap at 25 MB and Outlook.com at 20 MB. For anything longer than a 30-second clip, compression is required or you land in the auto-uploaded Drive/OneDrive fallback. Here's the math for each and Wave's role in the workflow.
What actually changes
Gmail caps at 25 MB per outgoing message (summed across attachments). Outlook.com caps at 20 MB per attachment; enterprise Outlook can go up to 150 MB when admin-allowed. Yahoo Mail and ProtonMail free both cap at 25 MB. When you exceed the cap, every provider silently offers a Drive/OneDrive/Mail Drop fallback - the recipient sees a shared-link card instead of an inline attachment, which works but loses the click-to-play preview. See Gmail and Outlook attachment size limits for the current per-provider caps and enterprise variations.
Bitrate targets by clip length for a 25 MB attachment: 30-second clip has ~6700 kbps for video (1080p high quality); 2-minute clip has ~1580 kbps (720p high quality); 5-minute clip has ~550 kbps (720p low or 480p acceptable); 10-minute clip has ~220 kbps (480p or drop resolution). Multiply by 0.8 for Outlook's 20 MB. The formula and mode choice (CRF, CBR, VBR) is in Video bitrate explained.
The common use case is a video call recording (Zoom, Teams, Google Meet) or a screen recording that needs to reach a colleague or client via email. Zoom local recordings typically land at 300-500 MB per hour of 720p meeting; Teams downloads at 400-800 MB per hour. Both need compression to fit the 25 MB cap for a full meeting, and both hit the Drive/OneDrive fallback if uploaded raw. For a 30-minute meeting, target-size compression to 25 MB means ~100 kbps video at 480p - only viable for pure talking-head content. For most real meetings, send a Drive link or trim to an excerpt.
Wave's role in an email workflow: (1) convert the source recording to MP4 - fixes MOV/MKV compatibility with older Outlook clients that don't preview them; (2) for inefficient source codecs, Wave's codec substitution during the MP4 conversion shrinks the file significantly. For the target-bitrate step, HandBrake or ffmpeg locally with the computed bitrate. If the recipient is on Gmail or Outlook.com, the Drive/OneDrive fallback is often the better UX than an over-compressed video - sender ships source quality; recipient chooses watch-inline or download.
Three steps.
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Step 1
For short clips (under 2 minutes at 720p): compress to fit 25 MB using HandBrake at RF 24-26 or the ffmpeg command above.
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Step 2
For medium clips (2-10 minutes): trim to the essential portion, convert with Wave to MP4 for compatibility, then target-bitrate compress.
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Step 3
For long recordings: use Gmail's Drive fallback or Outlook's OneDrive fallback. Send a link instead of an attachment.
Answers, specifically.
What is Gmail's attachment size limit?
25 MB per message, summed across all attachments. Larger files trigger the Google Drive fallback automatically - Gmail uploads to Drive and sends a link instead.
What is Outlook's attachment size limit?
20 MB for Outlook.com (personal/free tier); enterprise plans typically allow up to 150 MB when the admin has raised the cap. Larger files fall back to OneDrive share links.
How to fit a 30-minute Teams recording in 25 MB?
You can't at watchable quality. At 30 minutes, 25 MB works out to about 100 kbps video - only viable for pure talking-head content and even then rough. For a full 30-minute meeting, use OneDrive share (Outlook does this automatically) or trim to a specific 5-minute excerpt that compresses acceptably.
Gmail's Drive fallback - is it visible to the recipient?
Yes. The email arrives with a "Files added to Google Drive" bar and a preview thumbnail; the recipient clicks to open in Drive. It's a cleaner experience than a broken attachment but different from an inline video play. Drive-hosted videos support inline playback in Gmail's preview pane.
Can I encrypt the video before emailing?
The video itself, yes - password-protect the file (zip with password, or a signed / encrypted format). Neither Gmail nor Outlook does end-to-end encryption on attachments by default. For sensitive content, ProtonMail with the "Encrypted for external" option is the practical path.
Do email attachments compress on send?
No. Gmail, Outlook, and ProtonMail all send the attached file bit-for-bit. Any compression must happen before you attach. This is different from WhatsApp and Discord, which re-compress uploaded video server-side.
What if I need to send several video attachments in one message?
The 25 MB (Gmail) or 20 MB (Outlook.com) cap is the total across all attachments. Gmail's Drive fallback applies to the sum - if you attach two 15 MB videos, both auto-upload to Drive together and the message ships as one Drive link.