With a current setup of 2 mailbox email addresses, the first of which is setup on Thunderbird on a relatives PC, if I wanted to arrange for the second mailbox to redirect to the first (possibly as an alias?), would the second one's emails appear on Thunderbird with the first? I can't currently visit to make any changes to add the second account to Thunderbird on the PC because of the lockdown. I hope I've explained it clearly enough.
Fixed! Go to the fix.
Re: Alias or redirect
To accomplish what you asked, you would have to set up forwarding in your email client program (i.e. a manual setup) and would depend on if this advanced feature was available.