since I no longer have access to the old computer, I will be using the last option - which ‘clicked’ in my head shortly after I posted - by going to my sent folders which have all my emails way back to 2018 and have individually added them.
As you then no longer have access to your old computer, but your contacts automatically appear when you type them in the TO: line have you tried saving your recipient history as in my Exporting Contacts link above last part. See my extract below.
(To export your Recipient history to save to your Contacts).- eM Client V9.2 example)
Click “Menu / Settings (Preferences) / Mail / Compose”. Then click “Show Recipients”. Next “Select all your Recipients”, and then click “Save As”. Lastly “Choose your Contacts account folder” to save these to.
You can then save those in any account contacts or local folder contacts.
