Does Email Compress Photo Attachments?

Be careful with how far this answer stretches. The documented basis for it is Apple's own support page for Mail on Mac, and nothing else. That page is clear on two points: images go in at their actual size by default, and a size chooser appears in the message header when more than one size is available.

Other mail clients are not covered here. Different apps behave differently, and the honest position is that a claim about a client you have not checked is a guess. If you use a mail app that is not Mail on Mac, send yourself a test message with one photo attached, download the attachment from the received copy, and compare its file size against the file on your drive. That takes two minutes and it beats any article, including this one.

Also worth stating plainly: Apple does not document Mail recompressing your image or stripping information out of it, and this page does not claim that it does. The documented behaviour is a size choice offered to the sender, nothing more.

When a photographer asks whether email compresses photos, they are usually mixing two separate mechanisms that happen to produce the same complaint.

Attachment ceilings vary by provider and this page states no figure for any of them, because none was verified today. Assume yours is lower than a wedding and plan around it rather than testing it.

Compression is not the dangerous part. The dangerous part is that a reduced copy and the real file look identical once they land in someone's inbox. Both have your filename. Both open. Both look fine on a phone.

The client does not know which one they have. Two years later they take it to a print lab, the lab says it will not hold at the size they want, and the conversation comes back to you as a quality complaint about your work. Nothing in the email thread tells either of you which version went out, because the sent copy in your own mailbox is the one you composed, not necessarily the one that was transmitted.

This is the argument against sending files by email at all, and it does not depend on any compression claim. Attachments give you no record of what was delivered, no way to re-send when the client loses the message, and no way to correct a mistake after the fact. The message is gone the moment it is sent.

Sometimes a single image genuinely does belong in an email: one headshot for a press request, one frame for a magazine editor. In that case, export the file on purpose instead of dragging whatever thumbnail is on screen.

Apple documents that Photos on Mac can export the untouched original. Its export guide describes choosing File, then Export, then Export Unmodified Original, which exports "photos in the original file format in which they were imported." That is the setting to reach for when the point is fidelity rather than convenience.

The same page documents a normal export dialog with real controls: a JPEG Quality setting, a Size pop-up menu, a Color Profile choice, and an "Export IPTC as XMP" checkbox for metadata. It also documents JPEG, HEIC, TIFF and PNG as export formats, and states that "TIFF is a lossless file format" and that "PNG is another lossless file format." If you want the client to receive a specific thing, those four controls are where you decide what that thing is.

Then attach the file you just exported, from the folder you exported it to. Do not attach from a preview, a message thread, or a shared album. Every hop is another place a copy can be substituted for the original without anybody being told.

One file is a special case. A shoot is not. A wedding or a commercial day will not fit under any provider's attachment ceiling, so photographers split it across several emails, which is where delivery starts going wrong in four predictable ways.

• The client has to reassemble it. Six messages, six download folders, and no guarantee they got all six. Missing images surface weeks later.
• There is no record of what you sent. No list of images, no delivered-on date, no confirmation anyone opened anything.
• You cannot re-send. When the client changes jobs and loses the mailbox, your only recovery is to re-attach everything from your own archive.
• You cannot fix a mistake. A wrong crop or an unedited frame is out of your hands permanently once the message leaves.

None of that is a compression problem. It is a delivery-method problem, and it is solved by sending one link instead of files.

A gallery link replaces the attachment with an address. The email carries the link; the files stay somewhere you control, where you can correct, add and re-send without asking the client to dig through an old thread.

Here is how clientgallery.io handles it, stated exactly, including the part that cuts against us. The photos you upload for viewing are compressed in the browser into proof JPEGs before they are hosted. That is deliberate: it is what keeps a large gallery fast to scroll on a phone. So no, we are not a service that re-encodes nothing. We re-encode the proofs on purpose and say so.

Full-resolution delivery is a separate mechanism, and it is a paid one. You upload a full-resolution ZIP for a gallery, it stays live for three days per handoff, and you can re-upload it any time the client needs it again. Standing ZIPs are capped at 100 GB per account. Clients download the whole gallery in one click or take any single image, and hosted galleries never expire.

The plan is one plan: $10 a month or $100 a year. Unlimited galleries, photos and clients under fair use, where fair use means 1,000 photos per gallery and 250 GB of proofs per paid account, with 5 GB on a free account. Those are abuse tripwires, not a tier ladder, and they are published rather than hidden.

The practical result is the opposite of an attachment. You know the gallery exists, you know what is in it, and when the client asks for the files again in 2029 the link still works.

• Apple, "Send attachments in Mail on Mac" (Mail User Guide). https://support.apple.com/guide/mail/send-attachments-mlhlp1050/mac Fetched 23 September 2026.
• Apple, "Export photos, videos, slideshows, and memories on Mac" (Photos User Guide). https://support.apple.com/guide/photos/export-photos-videos-slideshows-and-memories-pht6e157c5f/mac Fetched 23 September 2026.