Here is how you set a db up for imap. https://www.ibm.com/support/knowledgecenter/en/SSKTMJ_8.5.3/com.ibm.help.domino.admin85.doc/H_MODIFYING_MAIL_FILES_TO_SUPPORT_IMAP.html
From what I can see they never exposed IMAP to lotusscript but perhaps using notespeek you can see a profile doc that might have been added/modified.
My suggestion is to try it on one db and then see what changes
You can turn on domino activity logging https://www.ibm.com/support/knowledgecenter/SSKTMJ_8.0.1/com.ibm.help.domino.admin.doc/DOC/H_VIEWING_ACTIVITY_LOGGING_DATA_OVER.html
Then write a batch file (via lotsscript) of telnet commands accessing the dbs (https://technet.microsoft.com/en-us/library/dd789687(v=exchg.80).aspx)
The activity will then show up in the activity log or if you want just redirect the out put to a txt file then view the txt file.