Importance of PTR Record for Mail Server

I have just realized why PTR record is really important. Many different people set different security settings on my mail server. What happen is that I found my mail server is rejected by several server because it’s missing PTR record. When my mail server connect to remote mail server, they only know my IP. In order to confirm my identity, they do a reverse lookup on my IP address to make sure that I’m sending on behalf of my domain only. This is one of the method to reduce spam, but it was causing havoc on my mail server. On the bright side, only several mail server are doing this.

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[SOLVED] Windows Live Messenger can’t login, but Windows Messenger can

This is happening at my friend’s PC. She uses Windows Live Messenger to chat for a long time when one day she can’t login. The MSN icon keeps on spinning forever, but the login process does not get completed. She found out that other PC in her house has no problem signing in, and Windows Messenger on her PC (the one built-in to Windows XP) also has no problem signing in. Turns out, the culprit is a registry entry. To fix this issue, I delete the following registry entry:


After I deleted the key, her account and my account can login on that PC.

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[SOLVED] Microsoft Exchange 16GB Limit

People who administers Microsoft Exchange does knows that Standard Edition Exchange do have a 16GB limitation on the Storage Group. When the storage is closing to 16GB, I always have to defragment the database. To do that, I have do the followings:

  • Dismount the storage space
  • eseutil /d "X:\Program Files\Exchsrvr\MDBDATA\priv1.edb" /t/temppriv.edb

    while replacing the path to the correct folder on the Exchange server

Another area that requires space (this time is hard drive space), is the transaction log. I have to set a daily backup schedule to backup Exchange, since it will also removes the transaction log.

Now we’re using the Exchange Advanced Server and there’s no more 16GB limit. The next step would be to upgrade the HDD (currently 76GB total space – in RAID5 configuration) so we have more space.

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