Usually I would say something about the tool that I talk about, but this time a quote from wiki.mikrotik.com (link) will do the job:
E-mail tool is the utility that allows to send e-mails from the router. Tool can be used to send regular configuration backups and exports to network administrator.
Email tool uses only plain authentication and tls encryption. Other methods are not supported.
All data that you need is here:
Server: 74.125.136.108 [smtp.gmail.com] <- you can't use hostname Port: 587 From: <your name> <- nice name User: <gmail username> <- without @gmail.com Password: <gmail password>
Configuring this tool is very simple, all you need to do is fill your data as shown in the picture
or you can do this in one step from the terminal:
/tool e-mail set address=74.125.136.108 from="<your name>" password=<gmail password> port=587 start-tls=yes user=<gmail username>
This is all you need to do… next time I will write some usage example. If you have some your example, you can leave it in a comment ;)