Touch and hold the attachment, then tap Markup (if it’s an attachment you’re sending) or “Markup and Reply” (if it’s an attachment you’ve received).
Use the drawing and annotation tools. See Use Markup in apps on iPhone.

An image in a Markup window. Below the image, from left to right, are buttons for the Markup tools: drawing pens, eraser, selection tool, colors, and buttons for adding a text box, your signature, and shapes, and for choosing the Magnifier.

Open an attachment with another app

Touch and hold the attachment until a menu appears.
Tap the app you want to use to open the attachment.

Note: Some attachments automatically show a banner with buttons you can use to open other apps.

See emails with attachments

Tap to turn on filtering.
Tap “Filtered by,” then turn on “Only Mail with Attachments.”

You can also use the Attachments mailbox, which shows emails with attachments from all accounts. To add it, tap Edit while viewing the Mailboxes list.

Send large attachments

Mail Drop is an iCloud feature that lets you send files exceeding the maximum size allowed by your email account. To use Mail Drop, tap Send when you’re ready to send an email with large attachments, then follow the onscreen instructions.

Mail must be turned on in Settings > [your name] > iCloud. See the Apple Support article Mail Drop limits.

To learn how to send any attachment, see Create an email message.

Helpful?

iPhone User Guide

Work with email attachments on iPhone

Preview an attachment

Save a photo or video attachment to Photos

Mark up attachments

Open an attachment with another app

See emails with attachments

Send large attachments