i can't able to access my email with gmail account

i use to link my domain mail account with gmail i can’t able to do ther was a error authentication failed. while i add a new email acount in gmail this is the error thrown by gmail
"Authentication failed. Please check your username/password.
[Server response: DNS Error: Address resolution of smtp.amitysoft.com. failed: Domain name not found code(0)]
i tried many times but the same error repeated 
i can able to access mail from my domain in gmail but i can’t send the mail from my domain…
i am new to this kindly help me to use my domain in gmail account

Hi Seshadri, what version of eM Client are you currently using, can you check for the exact version number in Help > About?
How did you setup the account, did you use the automatic setup?

If I understand this correctly you’re able to receive your messages but you’re unable to send? If there’s any error message displayed, can you please make a screenshot of such error and post it here on the forum?

Thank you,

Thank you for your reply Paul, Yes correct i can’t able to send mail but happens on gmail while “i add a new email account” tab in gmail i think this is IMAP somthing like that ,
the issue is already have a gmail account i going to merge this mail account “[email protected]” with this gmail account
i attached the screen shot below do the needfull… 

Hi Seshadri, unfortunately it seems like you’re not using the correct credentials for this account/domain. Please make sure you’re using the correct credentials and try to setup the alias again.

Thank you for understanding,