I would start with the new message files (.CNM) and the folder files (.PMM & .PMI).  AFAIK, the usage of these files hasn't changed since v3.5 and they may be the only ones you need if all you want to do is view message history on the tablet.

Maintaining this setup is going to be tricky because you can't sync all files in the mailbox directories (PC to tablet) and if you go the copy/overwrite route then folder deletes on the PC won't be reflected on the tablet.

It just dawned on me that the lack of HTML rendering in v3.5 may be a significant issue.

I am running 4.72.572 (build 572) on my Desktop PC with Windows 7 (Pro), but also want to be able to run Pegasus Mail on my Android (lollipop) Tablet if we experience a long power outage.

The idea is to copy the PMail directory each day to either a memory stick or directly on to the tablet (via USB connection) and then run Pegasus using DosBox Turbo (for Android). ** At this stage I probably would restrict activity to merely being able to read old emails and avoid trying to go online as this might complicate things (I can access new messages via Webmail if necessary).

I don't know if anyone has experience of this sort of thing -  I have downloaded pmail350.zip onto my PC - how should I go about unzipping it?

If I succeed in unzipping it and setting it up on the tablet, what's likely to happen if I then copy over all the files from PMail on the PC - which ones should I *not* transfer?

Not sure if you can simulate Window on Android as an alternative way forward but I suspect this would be resource heavy and raise other issues and vulnerabilities.

IIRC, back when v3.5 was released it could be extracted using a zip extractor like Winzip or 7-Zip.  I believe if DosBox Turbo would run v3.5 it would also run v4.72.  There are some features that will not work without the associated registry entries but if it DID run, you should at lease be able to view messages.  IMHO, I would just leave all messages on the server on use the Tablet to access it via webmail.

If you pursue running Pegasus Mail on the Tablet, there is a whitepaper in the downloads area of this site that should be helpful in determining which files to copy.  Find that whitepaper at: 

http://community.pmail.com/files/folders/whitepapers/entry41852.aspx

I've managed to extract v3.5 to a folder on the PC and then copied it to the tablet.

DosBox Turbo won't let me run v4.72, saying that it needs to run using Windows.

So far I have got DosBox to load up v3.5 but I now need to study the whitepaper you pointed me to. Thanks for the help - I'll let you know how it goes.  [:)]