[Exim] Still have SMTP Command Timeout Error

I am still getting a SMTP command timeout error. I happens intermittently.
Sometimes the address will get through, other times it will not. I am
considering adding a smtp_receive_timeout line to my config file. The
documentation says the default is 5m, is this milliseconds? What would be a
good value to try? If I wanted to double the time, would the line be
smtp_receive_timeout = 10m

Don Hammer
Network Administrator
Evanite Fiber Corporation
1115 SE Crystal Lake Dr
Corvallis, OR 97333
(541) 753-0391 voice
(541) 753-0388 fax
hammerd@???