Resetting my outbound mail server
I am currently on a MacBook Air running 10.10.2
I just installed a new wifi router, and now none of the 3 Macs in the house (all different operating systems) allow me to send mail from Mail (version 8.2 only laptop) through my internet service provider. I talked at length with the provider, and verified that all the account settings are correct. He suggested that a directory file may have gotten altered during the router installation, or something along those lines. I have a Motorola cable modem that has worked fine for years, the new NetGear wifi router, and a Verizon/Samsung Wireless Network Extender hooked up, which also seems to be working fine.
How can I get my outbound mail working again?
Thank you
MacBook Air, OS X Yosemite (10.10.2)