What happens when you have three linked accounts in the free version?

How does the free version of the eM Client handle it when you attempt to link a third account?  Here’s my experience:
For my own reasons, my email is actually filtered through three different email services - Comcast, Live, and Gmail.  It is normally sufficient to have only the Live and Gmail accounts linked to eM, but some time ago I had reason to try to link the Comcast account as well.  The client complained, but did link the account and I was able to see the contents.  I just left it that way – eM would gripe about not linking three accounts, but it worked fine.
Fine until I noticed that some of my emails were not being delivered.  To make a long story short, eM was routing some replies through the Comcast account even though every default setting says to use a different account.  The Comcast account does not deliver email, so the messages were stuck in message hell.  I found that I can change the “sent from” account on the message when replying, if I remembered to do so (but often did not!).
My only recourse to prevent this was to remove the third linked account from eM, which it had so graciously allowed earlier, but so severely warned me about.
Funny how things work out. 

You can configure a third account, but it won’t work.
If you want to make it work, you have to disable one of he two others I think.
Besides the program will warn you about what you can not do…