1. Leverage User Group

ZOHO provides 25 users accounts under their free plan: that means you can support up to 25 individuals in the organisations. For those autonomous and generalised email address, you can make use of the user groups instead.

There is no limit in creating user group email address and alias. In fact, you should do it that way since:

1. It is a group email by nature itself. Example, say a customer send an email to inquiry@mycompany.com, at the end of the day, it is human who is going to respond it. Hence, it's better to group your first tier customer service team members under "Customer service" with that email alias.
2. ZOHO Mail allows public mail sending so you do not need to worry about it.

3. Personal Use - Integrate with Google Drive for Documents

The thing about ZOHO 5GB storage space for each email accounts is a combined total spaces from ZDocs and ZOHO Mail. If you're running a non-commercial use, one way to reserve the the entire 5GB storage is to leverage Google Drive into your advantages.

The steps here are mainly to cover a non-business team use. Remember, personal Google Account is only for personal use. Using personal Google Account for business is a direct violation of their terms of service. For established business accounts, you can consider sign up for G-Suites for their fully integrated office software integration.

Manage your Google Drive root folder using a Team Account

Google allows Google Account creation using non-gmail email address through their Sign Up Without Gmail portal. You can first create the root team account that holds the ownerships of all files. You can use your "tech@mydomainname.com" email alias as a start.

Managing Members

Now, you need to set a team policy that no one should share any folder or contents for email address other than your domain name. Each members should only use their ZOHO Mail Google Account through Sign Up Without Gmail portal.

To ensure your members comply to your team policy, you can organise a bi-weekly folder audit to ensure no alien email is in your folder.

Managing Your Member's Leaving

If say one of your member decided to leave your team, team leader can have a 1:1 meeting to that member for access removal.

Firstly, team leader must work that member for resetting his/her ZOHO Mail Google Account on your side by assigning a recoverable new password not known to that member. This will seal all access for the member to login to your team folders.

Secondly, have a folders audit to ensure that no personal or alien email address is in the root folder. Once completed, you may close his/her ZOHO Mail account on ZOHO side while the contents in the Google Drive stays as it is.