Hi, can you manually use commands to test the U/P are working from your postfix server ?
1. Run this to test connectivity to your server openssl s_client -starttls smtp -connect your.host.name:587 Typical OUTPUT = 250 DSN quit 221 2.0.0 Bye closed 2. Run this to create a hash python -c 'import base64,sys; u,p=sys.argv[1:3]; print base64.encodestring("%s\x00%s\x00%s" % (u,u,p))' username password OUTPUT = dXNlcm5hbWUAdXNlcm5hbWUAcGFzc3dvcmQ= Replace username and password with real ones Once Steps 1 and 2 work, you can test authentication with the hash in Step 3 3. Run the openssl commands and connect to your server. A. do and "ehlo domain" to see commands supported EXAMPLE : ehlo domain 250-localpart.domain.part 250-PIPELINING 250-SIZE 31457280 250-VRFY 250-ETRN 250-AUTH PLAIN LOGIN 250-ENHANCEDSTATUSCODES 250-8BITMIME 250 DSN B. execute the AUTH PLAIN LOGIN command option using the HASH you made in Step 3 AUTH PLAIN dXNlcm5hbWUAdXNlcm5hbWUAcGFzc3dvcmQ= C. look for output 235 2.7.0 Authentication successful -ANGELO FAZZINA ITS Service Manager: Spam and Virus Prevention Mass Mailing G Suite/Gmail ang...@uconn.edu University of Connecticut, ITS, SSG, Server Systems 860-486-9075 -----Original Message----- From: owner-postfix-us...@postfix.org <owner-postfix-us...@postfix.org> On Behalf Of Michael Sent: Monday, January 14, 2019 1:00 PM To: postfix-users@postfix.org Subject: Re: New SASL error when relaying through gmail On 1/14/19 10:42 AM, Christopher van de Sande wrote: > Just a guess, but are you using App passwords for GMail? It's > possible Gmail is enforcing some 2FA/MFA or otherwise some kind of > "enhanced" authentication. > > Even if you aren't using 2FA, it might be worth giving a shot. > >> I thought this might be the case as well. I reset the password the >> account password and also re-setup the application password on the >> gmail account for postfix (in my my sasl password file). That didn't >> seem to make a difference. Is there an easy way to test the app >> password on google? >> >> >> Michael >> >> I went back into my account and turned on less secure apps and turned off 2FA. I tried again with the regular password and the app password. Still the same error. I hate when things work and then suddenly break :( Michael