You're wanting simultaneous access to what I infer is a POP account. Coordinating shared, concurrent access to a POP file would require an intermediary client. My suggestion is to create a third account that just contains account A and remove it from the other two accounts. While changing the location would solve the disk space issue, it would not resolve the concurrent use issue.

Only if the two users never, ever use their profiles at the same time - without exception - and each quits thunderbird before the other uses thunderbird.

That's even more justification for a third profile.

Hi David and thanks for your reply.

I got that option enabled for another account that is not being used all the time by the users. I even created an access in the desktop so that they can open the profile directly.

This option with 2 or 3 TB concurrent instances it is not only hard for working, it is a REAL MEMORY EATER and this would generate a different problem with the actual resources.

If I could change internally the folder/path for the inbox folder I could free more than 40 GB of disk space.

Thanks for your help but I think that this is not suitable for my environment.

I did not mean to imply that it cannot be done; I was proposing what would be the simplest to achieve the goal.

Yes David, you are right.

That is why I used that option for the other account that is not being used all the time.

Thanks Wayne, as you wrote, both profiles will never be used at the same time.

If users/profiles will not be used at the same time, then I think my recommendation of pointing the ACCOUNT storage to a shared location will work, even for pop, because popstate.dat is located in the account's directory structure. In that case a) they would be sharing ALL the folders of that account, not just Inbox, b) you better have very good backups in case something goes sideways

Hi again to all,

I am very sorry for this reply to be so spaced in time but I couldn't be over this matter again until I had some free time.

There is a saying that the simplest solution is usually the best, and in this case, it worked for me !!.

After searching the routes in the SQL-LITE files ... , then I checked the account configuration and I realized that in bottom of the server config appears the LOCAL PATH/ROUTE for that account. So, I dedided to overwrite the route in one profile and use the same route for both profiles.

I am just proving this in production but it seems that it will work fine, the only problem is that both persons will share the account data but this is perfect for me.

If this option works fine and without incidents, I will close the case. I prefer to be sure !!

Thanks to all for your help !!

Best Regards

Hi again and thanks to all.

By the moment, everything is working fine and without issues and it is based on Wayne Mery's solution.

SOLVED !!!

Best Regards