how to send file as attachment using mail or mailx

I have a need to send a file from the unix command line to be sent as an attachment. Is this possible? That is when I open my outlook email I need to file to appear as an attachment.

Also, is there a way to use the mail binary (not mailx) to modify the "reply address". mailx -r works but I need to use mail and this does not have that option.

Thanks.

Please use the Forums 'Search' function and look through the FAQ section - these questions have been asked/answered many time already.