If you're having trouble sending, receiving, or viewing attachments, it could be a problem with your browser settings, file size, file name, or unsupported file encryption.
If you can't find downloaded attachments and basic browser troubleshooting hasn't helped, check your browser download settings, located in the Options, Tools, or Preferences menu of your browser. There you can change your download settings and select where you'd like your downloads saved.
Reduce file size With AT&T Email, you can attach up to 50 files to an email message with a maximum total message size of 25MB. If you need to send files over 25MB, try using a free file hosting service like Dropbox or YouSendIt.
Remove special characters from a file name Be sure that you haven't used any special characters like #, $, /, or @ in your file name, because these characters can cause problems in sending.
Reformat encrypted files If the attachment looks garbled or won't open, it's possible that it's in an encrypted format. Encryption can only work if both the sender and recipient have the key to decode it, so it's best to ask the sender to resend an unencrypted file. Also, be sure that files you send are not encrypted.