Blocked User without a license still has email?

[ViProCon]

Hi all.  I know that going into the Office 365 Admin Center and setting a user to be Blocked from sign-in has no impact on their email coming and going.  But if I remove their Office 365 license so they have no products linked to their account (so it can be reclaimed and given to another user), will that set their mailbox to be deleted at some point?  

And perhaps a more granular version of this question:  if we take away that user's license, but not assign that license to anyone else, therefore we have "1 of xx licenses available" either for this or a new user, will that be any different?  

The scenario is just that the company would like to retain access to the user's old emails, but not waste a license on keeping that account 'active'.  Thanks!  

[#2 · Accepted solution]

convert to shared mailbox and then remove the license.

[#3]

Ok follow-up question: what is the retention period for mailbox data if I had removed the license some months ago? Just now, I re-enabled sign-in, re-assigned the one available EOP1 license, gave it about 30 minutes, then logged in as the user. OWA opens fine so the license is provisioned, but, there is zero data in any folders. Is there a chance this is tucked away somewhere in Exchange Online where it can be recovered? Similar to the OneDrive 180 day retention in the recycle bin type thing?
I assume at this point, converting to Shared Mailbox wouldn't suddenly bring back the old data, so I'll have to remember that for future use.
Thanks again!

[#4]

For mailboxes, data is retained for 30 days only once license is removed. So remember to convert to shared first before removing any license.

[#5]

@DeepakRandhawa  Thanks very much for the info.