What does the SMS limit per conversation do? On the Samsung Galaxy S3, there is an option under the default SMS application called "Beschränkung für SMS" ("limit for SMS"). It was set to "200 messages per conversation" when I bought the phone.

What does it do? What happens to messages exceeding this limit? Is there any reason that I can't save millions of messages per conversation?
What happens is this, depending on the settings within SMS App, (really its actually MMS app), 'Delete Old Messages' option Delete old messages as limits are reached, if that was checked, then once it hits the threshold of 200 texts, Android will wipe them, to make room for more incoming messages.

Now, If that was not checked, Android does nothing but... it will slow down the handset to a crawl because it is loaded down with say, hundreds of messages, because Android is keeping track of it.

If you really care about your SMS, it might be best to use SMS Backup Restore and just back them up periodically.