E-mail service providers may impose a cap on the size of file attachments that you can send and receive. Yahoo! and Gmail are examples of Web-based mail brands that have such a restriction. This means that you can attach only as many files to a single message as meet the size limit if you're the sender. If you're the recipient, you can't receive messages that exceed the limit.
Yahoo! Mail allows a total final attachment size of 25MB per message. This figure must include the size increase that occurs during encoding. When you attach a file to a message, Yahoo! encodes the file to make it readable by e-mail clients. Unfortunately, encoding increases the size of the file by about one third, or 33 per cent. Further, upgrading to Yahoo! Mail Plus doesn't increase the total attachment size limit.
Like Yahoo!, Gmail limits the size of attachments you can send and receive to 25MB per message. If the files you select exceed this limit, Gmail will let you know and ask you to select fewer files. Besides the size limit, Gmail doesn't allow you to send a zip file if it contains an executable file (such as EXE files) or is encrypted with another zip archive inside it.
Even if the attached files don't exceed the size limit, your recipient may still not receive them if his mailbox has a smaller size limit than Yahoo! or Gmail. If this is the case, you can invite the recipient to open a new e-mail account with either Yahoo!, Gmail or another Web-based mail service that has a generous size limit.
If the total size of the files exceed the limit in either Gmail or Yahoo!, you can still share them. Create multiple messages and distribute the files among them, making sure each batch is below the limit. You can also compress files with a zip utility program. If you change your mind after attaching a file, you can remove it by clicking the "X" button next to the file in Yahoo! In Gmail, you can either clear the check box for the file or click "Remove."