Maximum Size of Attachments in the iPhone

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Connecting your iPhone to your company email account or a Web-based email service such as Gmail allows you to send and receive work documents on your phone wherever you go. Although not all types of files will open on the iPhone, depending on the apps you have installed, there is no set limit on the size of files you can email through your iPhone. Your email service, however, may apply its own limits.

iPhone Limitations

Neither the iPhone hardware nor iOS directly impose a cap on the size of attachments. Through the Mail app or third-party apps with emailing capabilities, you can attach and send any sharable file on your phone, regardless of size. Similarly, you can download attachments of any size onto your iPhone, although iOS does not support as wide a range of file types as a computer does. The only limitation to downloading attachments is your phone's free memory space.

Sending Limits

Your email provider may impose its own limits on attachment sizes. These limits apply to files sent or received using your iPhone, just as they do on your computer. If you try to send a message with an attachment that is too large for your email provider, the message will fail. If someone else tries to send you an attachment larger than your email provider supports, you will not be able to download it.

Recipient Limits

Even if you attach a file small enough for your email provider's rules, it may not send correctly if your recipients' emails do not support as large attachments. Depending on their email providers, the message may arrive without the attachment or it may bounce back entirely. To avoid issues, try to keep your attachments as small as possible.

Workarounds

To get around attachment size limits, you can upload a large file to an online storage service instead of emailing it directly. Many services, such as Dropbox, Box, Google Drive and Microsoft's SkyDrive offer iPhone apps. You can upload files directly from your iPhone to one of these services and then share a link to the file instead of attaching it. When combining some email services with specific storage services – such as Google Drive with Gmail, Dropbox with Yahoo or SkyDrive with Outlook – the file appears to the recipient directly in the email, as if you had attached it.