Very best would be a complete clone of the Drive so Setup Assistant/Migration Assistant can import & convert all your stuff on the new one.
First Quit Mail, then I'd backup these two Mail folders, by right clicking on them in the Finder, then choose Archive/Compress.
(Could be a different folder here if you chose such in Mail Prefs)
Right click on that Mail folder, choose archive, you'll get everything in the folder, and the folder itself in a file called Mail.zip, move it to a safe place, same for the Mail Downloads folder... only the plist is separate.
For Address Book, quit AB...
Though for AB, selecting All & exporting as a vCard file is more useful.
I take backups of my photos, music, etc. every six months for offsite storage. I would like to add my mail to this process (I have onsite backup of the entire system covered.) The directory specified in this stream
does not exist on my Mac OS X 10.7.5. Can someone tell me where else I should be looking?
Your problem is not the same as that of the original poster of this older thread, and it can be very confusing for everybody if we try to answer more than one question in each thread.
In order for us to give your problem our undivided attention to try to solve it, would you kindly start your own thread, describing the trouble you are having in the fullest detail, including completing your details to show what Mac you are using, what operating system, and what version of the application in question. Please remember to post in the forum relevant to your hardware or version of OS X.
This forum is for Tiger OS 10.4. You are running Lion OS 10.7