EMAIL->SMS gateways for various carriers and/or SMS services for individuals?

Question

Email

The essence of the task:
Notify registered users of the service about events that have occurred on the service.
Frequency - a dozen pieces per day, there is no question of mass mailings!
It is possible to send a message through the EMAIL2SMS gateways of mobile operators, but in reality only the Megafon gateway works.
I would like to know the gateways of other operators by def codes. It is possible in a personal.
The option of using an external service to send via HTTP GET / POST is also being considered.
I would like it to be free, but a commercial option will also be considered, but for an individual.
PS The option using a GSM modem is not implemented, because hosting is at a remote site (in another city).
PPS A search in Google and Yandex returned a lot of EMAIL2SMS gateways, but as I wrote above, only Megafon ones work, so you need up-to-date and verified information.

Answer 1

In reality, the gateway works for the beeline too, but the subscriber needs 1 action to allow the reception of such SMS.

Answer 2

This issue has already been discussed.

Answer 3

Email2sms works for everyone, only for those who need to turn it on for the subscriber himself.

Answer 4

You would not be chasing the pop for the cheapness of the free.
Take sms.ru, smsrent.ru, with large volumes, prices are reduced

Answer 5

smsc.ru is very loyal. Although earlier (I think) it was even better.