And about merging all records from all profiles in one list. At least in one case it is not quite right. I have some "paired" users with different legacyExchangeDN attribute, proxyAddress but with the same e-mail address and the same mail nick and one is visible in GAL of one account and not visible in GAL of other account and other user is vise versa. I saw 2 different .dat files for two accounts by NK2Edit, these users are correctly stored (saved) to these files, has almost the same record weight, but OL2010 shows only last used for sending to record not matter which account is used at the moment account (meaning - first sending to: user1 <user[at]domain> from account2; second sending to: user2 <user[at]domain> from account1, and suggested user2 <user[at]domain> only) . Such paired user is to allow some multitenant configuration in Exchange installed not as "Hosted" . The most right way of per account Autocomplete list is enquiring Exchange mdb storage, and showing list (that is suggested) from data got from mapi property (I wrote above) from IPM.Configuration.Autocomplete class message only and these values should be written to local .dat files and got in the same way of getting from Exchange if it is down. By the way, Autocomplete list works correctly even for such "paired" users when I use multi OL instances (with ExtraOutlook) .