I want to learn step by step smtp server configuration and than generate backup and send it by e-mail to my e-mail and i want that monthly automatically. i am trying this ex. " https://wiki.mikrotik.com/wiki/Manual:S ... _by_e-mail " . i have gmail address and you can see my Forwarding and POP/IMAP settings in gmail.

I am doing exactly that. Here are the settings:
First setup your E-Mail server information. I am using a G-Mail account.
Then the script that creates the files and sends them:

Then set a schedule. In my case, this router sends backups every day at 22:32:00:

YES thnks. i have one more question if you can halp when internet usage falls below 10 Mbit and if it exceeds 100 Mbit,can we send e-mail?

Hi,

I did it in another way, I remove the file before to create new one, but not after delay for mailing:

/file remove [find name="email_bak.backup"];
/system backup save name=email_bak;
:delay 5;
/tool e-mail send file="email_bak.backup" to="xxxxx@gmail.com" from=yyyyy@gmail.com body="See attached file" subject="Mikrotik Backup $[/system identity get name] $[/system clock get date] $[/system clock get time]";

But my question is it possible to save backup file only if settings were changed, for example if last record (but record #0) in "/system history" has later date/time than date/time of existed backup file?
IMHO it seems too much for my charisma to have daily greetings from routers lol, I would like to have the backup just after change only.

The change-only determination is probably too difficult to be worth the effort. You can't compare files in RouterOS (string variables have definite maximum lengths) and there is no easy indicator for "date configuration last modified."

One comment I will make is that I would recommend you use export, and mail the results of that, instead of mailing backup files. Backup files are comparatively huge, many email servers will not accept them, and they are only good for the physical board they were made from; whereas rsc files are smaller, can be used to "clone" to a new board if the old one gets hit by lightning, and can be compared with a simple diff application.

We have all our units email fresh rsc exports to an archival account twice per week, we save the first copy as a baseline, and whenever we need to do a comparison, after we approve the current configuration as acceptable, we copy that to the baseline instead.

The change-only determination is probably too difficult to be worth the effort. You can't compare files in RouterOS (string variables have definite maximum lengths) and there is no easy indicator for "date configuration last modified."

Yeap, you're right. /system history is active only during the user's session. On regular basis only /log is used and there we don't have opportunity to track the changes.

One comment I will make is that I would recommend you use export, and mail the results of that, instead of mailing backup files. Backup files are comparatively huge, many email servers will not accept them, and they are only good for the physical board they were made from; whereas rsc files are smaller, can be used to "clone" to a new board if the old one gets hit by lightning, and can be compared with a simple diff application.

We have all our units email fresh rsc exports to an archival account twice per week, we save the first copy as a baseline, and whenever we need to do a comparison, after we approve the current configuration as acceptable, we copy that to the baseline instead.

That's correct, you are right again. import file after first connect, reboot and that's all.