Yes. Attachments are limited to a maximum size of 30 MB (megabytes). Please keep in mind that it will take longer for the recipient to receive the message than it took you to send it. Large attachments can fill the recipient's mailbox or cause the mailbox to lock up, preventing the recipient from receiving any other email.
Note: Attachments are limited to a maximum size of 30MB in Webmail, and 15MB in other e-mail programs. The overall e-mail (including attachments with encoding) cannot exceed 30MB when sending. E-mail attachments are base64 encoded, which will make the attachments about 30-40% larger than the original file. For example, 20MB of jpg files could easily exceed 25MB when base64 encoded.