What is the best way to reorganize free corporate mail to increase the size of the mailboxes?

Question

gmail

There is a corporate mail, registered for a long time for free on GMAIL.COM and suits everyone. For each free box, GOOGLE allocates 15 GB - it seems like a lot, but now the letters have become catastrophically heavier, and the people began to quickly run out of space in the boxes. Well, I say, clean it up - And we need EVERYTHING there, there is nothing to delete. And even if they rake a little, the boxes fill up again in a moment.
Now about 50 mailboxes are used, the maximum possible number is 100 for free. I
see solutions, but I can’t choose: 2. Rename mailboxes to [email protected] (such as an archive) as they fill up and create empty [email protected] mailboxes
3. Migrate to Yandex.Mail for Domain or "Mail for Site" from Mail.Ru - they have unlimited mailboxes.
4. I REALLY DO NOT WANT to start my own mail server - I already had experience in dealing with spam and viruses. Letters either do not come to us, or they do not reach customers, or the encoding breaks. And now there are mobile employees, except for office ones, and they need access to mail ... I would like to shift all this smut to a third-party service.
5. More options?
Please share your positive experience in solving similar problems.

Answer 1

They also kept mail at first on Google Apps at a time when there was a free limit of 10 mailboxes. Then they made their own mail server, and yes, spam was a mess, the server went down and mail went down, several gigabytes of logs due to a hacking attempt, in general, they abandoned everything and switched to Yandex.Mail and domains were transferred to their DNS servers. In general, we are very satisfied, everything works and everything comes, the mail is autonomous and has no restrictions.