Apple's Mail Drop limits page gives one number for the attachment and one for the account: "With Mail Drop, you can send attachments up to 5 GB in size," measured against a "1 TB Mail Drop storage limit." Everything else people argue about — expiry, file types, whether it eats into your iCloud plan — is written on that same page, and two of the answers are the opposite of what most people assume.
Here is each number, what it is actually measured on, and the fix Apple itself recommends when you are over.
The limits, at a glance
| What | Apple's figure | Scope |
|---|---|---|
| Attachment size | up to 5 GB | Per message: the error text reads "The message, including its attachments, is larger than 5 GB" |
| Mail Drop storage | 1 TB | Your total Mail Drop pool, not per message |
| Attachment expiry | 30 days | "Each attachment expires after 30 days" |
| Recipient download window | 30 days | Starts when you send, not when they open it |
| Supported file types | "All files types are supported" | Apple's wording, verbatim |
| Counts against iCloud storage | No | "attachments don't count against your iCloud storage" |
| Downloads allowed per link | see official docs | Check the current behaviour in Apple's Mail Drop limits page |
Every row above is quoted from that one page. If a number you read elsewhere is not on it, treat it as folklore.
The two facts people get wrong
1. Mail Drop attachments do not consume your iCloud storage. Apple states it in a single sentence: "All files types are supported and attachments don't count against your iCloud storage." So a 5 GB video you Mail Drop does not push you toward the upgrade prompt on a 5 GB iCloud plan. The 1 TB Mail Drop pool is a separate allowance.
2. The 5 GB is measured on the message, not on the file. The failure text Apple documents is "The message, including its attachments, is larger than 5 GB" — so three 2 GB clips in one email is a different situation from three separate emails, even though the largest single file is well under the cap.
Why the 1 TB pool is a rolling limit, not a hard wall
The 1 TB figure sounds like a ceiling you eventually hit and live with. Apple describes it as self-clearing:
"You reached the 1 TB Mail Drop storage limit. Each attachment expires after 30 days, so you can send new attachments after earlier attachments expire and more storage becomes available."
Two consequences worth planning around:
- Space comes back on its own, 30 days after each send. If you are near the ceiling, the oldest attachments free themselves first.
- The 30-day clock is also the recipient's deadline. Apple puts it plainly: "After you send an email, the recipients have 30 days to download the Mail Drop attachments." Send a wedding video on the 1st and the link is not something the recipient can sit on for two months.
When Mail Drop is offered at all
Mail Drop is not always the first thing that happens when you attach something large. Apple ties the prompt to your mail provider's own ceiling:
"If a message, including its attachments, is larger than your Internet Service Provider (ISP) limit, Mail will ask you to send the attachments using Mail Drop."
That matches how Apple describes attachment limits elsewhere. The iPhone User Guide's sharing page carries a blunt note: "The size limit of attachments is determined by your service provider." In other words, the number that triggers Mail Drop is not Apple's to publish — it belongs to whoever runs your mailbox. If you want a concrete comparison point, the way Gmail's attachment size limit works is a useful reference for how providers draw that line.
What to do when you are over 5 GB
Apple gives exactly two remedies in the same error message, and there is no third:
"Try sending the contents of your message in multiple email messages or compressing your attachments to make them as small as possible."
Splitting is fine for a batch of separate files. For one long video it is the worse option — the recipient ends up with parts to reassemble. Compressing is the option that keeps a single playable file, and for camera video there is usually a lot of room: Apple's iOS 18 User Guide notes that "one minute of regular 1080p 30 fps video is approximately 65 MB." Note the scope — that figure is stated for 1080p at 30 fps. For 4K, 60 fps or ProRes, check the current figures in Apple's official documentation rather than extrapolating.
Try it right here
Runs in your browser. Your file is not uploaded anywhere.
This runs in your browser tab: the file is read from disk, re-encoded locally, and handed back. Nothing is uploaded, which matters when the thing you are trying to email is the sort of footage you would not hand to a random web service. See all Clapr tools for the rest, or compress video if you want the general-purpose version with the knobs exposed.
Gotchas that are not about the 5 GB
The recipient's mail app has its own limit. Apple's page flags this directly: "The recipient's email app might have a smaller message size limit that prevents the attachment from being delivered." Mail Drop sends a link rather than the payload, but the message carrying it still has to land in their inbox.
Emailing video can change its format. On HEIF and HEVC, Apple writes that "if sharing this media using other methods, such as AirDrop, Messages, or email, and the receiving device doesn't support the newer media formats, the media might automatically be shared in a more compatible format, such as JPEG or H.264." Note the two qualifiers Apple keeps: might, and only when the receiving device doesn't support the newer formats.
The share sheet has its own format switch. The iPhone User Guide (iOS 27) describes it as: "Adjust the file format: Tap Automatic for the best file format for the destination, tap Current to prevent a file format conversion, or tap Most Compatible and files may convert to JPEG or MOV." Current is the official way to stop a conversion. If you are dealing with a QuickTime file on the other end, MOV to MP4 handles the container afterwards.
Mail Drop is not the only large-file route. The iOS 26 version of Apple's "Share long videos on iPhone" page documents an iCloud Link path — "An iCloud Link is a URL that you can use to send a large video with Messages or Mail" — and gives it the same window: "Recipients have 30 days to download a video sent with an iCloud Link." The iOS 27 version of that page still opens by saying you can use "AirDrop, iCloud, or Mail Drop," while its body covers AirDrop and Mail Drop. If you want the iCloud Link steps, the iOS 26 page is where they are written out.
FAQ
How big can a Mail Drop attachment be on iPhone? Up to 5 GB, per Apple's Mail Drop limits page. The check applies to the message including its attachments, so several medium files in one email can trip it even when no single file is close to 5 GB.
Does Mail Drop use my iCloud storage? No. Apple states that "attachments don't count against your iCloud storage." Mail Drop has its own 1 TB allowance instead.
How long do Mail Drop attachments last? 30 days. Each attachment expires after 30 days, and recipients have 30 days from when you send to download them.
What happens when I hit the 1 TB Mail Drop storage limit? You wait it out or send less. Apple's guidance is that you can send new attachments once earlier ones expire and free up space — the pool refills as the 30-day expiries land.
Why did my recipient never receive the Mail Drop link? One documented cause is on their side: their email app "might have a smaller message size limit that prevents the attachment from being delivered." Sending a compressed file as a normal attachment sometimes gets through where the Mail Drop message did not.
What file types can Mail Drop send? Apple's wording is "All files types are supported." Format restrictions you run into are more likely to come from the receiving mail service than from Mail Drop.
More on where platforms draw these lines: the limits hub. Figures on this page are quoted from Apple's Mail Drop limits article and the iPhone User Guide, checked 21 September 2026 — verify against the official pages before relying on them.
