Maximum Attachment Size for 1&1 E-mail Accounts

The maximum attachment size for all 1&1 basic e-mail accounts is limited to ~75MB. Because of base64 encoding (used when sending attachments), the maximum attachment size may be less depending on the type of file(s). This is a result of the base64 encoding which commonly increases file size slightly. This limit remains the same whether you are using the 1&1 Webmail interface or sending mail through an e-mail program.