Outgoing mail giving me 'incorrect password' error

Outgoing mail giving me 'incorrect password' error

I am able to receive email on my MacBook Pro, but cannot reply or send without receiving the password error. 
Is this an issue with two-factor authentication? If I create an Account Specific password for the laptop, will this affect my other devices and give me login errors for them? (iMac desktop and iPhone, both of which seem to be working)?