问题
I'm having trouble configuring Postfix to deliver e-mail via relay to Sendgrid.
I get the following error: "Unauthenticated senders not allowed"
回答1:
Looks like it was the SASL config within Postfix authenticating to Sendgrid. We were able to use the following:
smtpd_sasl_local_domain = $myhostname
smtpd_recipient_restrictions = permit_sasl_authenticated, permit_mynetworks, reject_unauth_destination
mailbox_size_limit = 256000000
# Sendgrid Settings
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = static:SENDGRID_ACCOUNT_EMAIL_HERE:PASSWORD_HERE
smtp_sasl_security_options = noanonymous
smtp_tls_security_level = may
header_size_limit = 4096000
relayhost = [smtp.sendgrid.net]:587
来源：https://stackoverflow.com/questions/9791735/fix-postfix-authentication-for-sendgrid