Supporting the quoted-printable encoding type, and using this support to create more efficient messages.

Limiting single-attachment messages to a single content type, instead of using the current multipart-mixed wrapper where it is not necessary.

Making an effort to determine the sender (such as by system username and local hostname) when a From address isn’t given. Perhaps in these days of spam, the user should be forced to give a verifiable mail address before the script will mail a message.

Adding to the capabilities of the getContentType subroutine. Besides file extensions, one could determine content types by running the Unix file utility (if present on the system) on files to attach.

Adding support for custom or user-defined headers.

Adding support for URLs in the attachments list so that one could attach files from the network.

Fixing “manpage” to return documentation for all operating systems (e.g., Microsoft Windows NT), perhaps by using the Pod::Text module on CPAN.

Creating a more robust expect subroutine.

Insisting on a proper name for the localhost, perhaps by using the Sys::Hostname module on CPAN. This would allow one to properly provide the sender’s local machine name to an SMTP HELO or EHLO command.