The administrative office is currently using one G Suite/Gmail address that is being accessed by two people at the same time ( let's say Sue and Mary, they work in the same room). Effective (everyone can see who replied to what), but not elegant. I don't like that!

In an ideal world, there should be a distribution list for the administrative office and two personal accounts in the list, however it gets tricky when managing replies.

Scenario:

• administrative@myorg.com is the distribution list
• sue@myorg.com first email in the distribution list
• mary@myorg.com second email in the distribution list

Problem
One day Mr Red sends an email to the distribution list administrative@myorg.com and both Sue and Mary will receive the same email, however Sue is out of office and Mary will reply to Mr. Red.
The next day, Mary is out of office and Sue will open the email and reply to the same email from Mr. Red as she doesn't know that Mary has answered already.

An idea could be to use one account administrative@myorg.com with two aliases (personal names). Both users would access the same inbox and see who did what. But we are still using one account for two people…

I am aware of collaborative inbox as a tool, however it's design and feel looks more appropriated for a tech support "threading" tool…

Better ideas?