I have had the same problem.
After upgrading to version 3.24 the problem dissapeared.
You can already do this with netflow.
from my experience the best signal is in range -60...-70 and i do my best to keep the clients in this range.
What was the problem ???Thanks Janisk for the repply through email.
And for everyone else. According to Janisk, the DNS problem will be fixed in the next release. Woooohoooo!
Probably you have problem with the script syntax, that is translating dns-name,
as I do not have any problems to send e-mail from 3.0rc1 router (when correct configuration is used).