Cost / License
- Free
- Proprietary
Platforms
- Windows

Mailer is described as 'Free utility to send emails from the command line. No Installation. All contained in one file' and is an app in the os & utilities category. There are five alternatives to Mailer for Windows, Linux and Mac. The best Mailer alternative is CMail, which is free. Other great apps like Mailer are blat, sSMTP, mailsend-go and chefsender.

Blat is a small, efficent SMTP command line mailer for Windows. It is the SMTP sending part of an eMail User Agent (MUA) or eMail client. As such, Blat sends eMail via SMTP (or internet eMail) from the command line, or CGI.
mailsend-go is a command line tool to send mail via SMTP protocol. This is the golang incarnation of the C version of mailsend. However, this version is much simpler and all the heavy lifting is done by the package gomail.v2
You can send the mails via an smtp server, such as blat, supports authentication and ssl. In addition, he can also send emails via the OWA interface (i.e. the Exchange Server can also be used for external sending if the OWA is published).