Email Sending Issues Occured on Different Email Provider on notification_email and reply_by_email_addresses

sptrf · August 28, 2021, 3:13pm

After some investigation, I guess this problem may be related to the conflict between the notification_email and reply_by_email_addresses. When the two variables are both configured, the outgoing email seems using reply_by_email_addresses as their from: address, which may be related to the code below:

github.com/discourse/discourse

lib/email/message_builder.rb

1472e47aa


      
              end
          end
          
          def alias_email(source)
            return source if @opts[:from_alias].blank? &&
              SiteSetting.email_site_title.blank? &&
              SiteSetting.title.blank?
          
            if @opts[:from_alias].present?
              %Q|"#{Email.cleanup_alias(@opts[:from_alias])}" <#{source}>|
            elsif source == SiteSetting.notification_email || source == SiteSetting.reply_by_email_address
              site_alias_email(source)
            else
              source
            end
          end
          
          def site_alias_email(source)
            from_alias = Email.site_title
            %Q|"#{Email.cleanup_alias(from_alias)}" <#{source}>|
          end

However, when I switch the notification email to office 365 with the similar SMTP configuration, the email sends without any problem.

  #DISCOURSE_SMTP_ADDRESS: outlook.office365.com
  #DISCOURSE_SMTP_AUTHENTICATION: login
  #DISCOURSE_SMTP_ENABLE_START_TLS: true
  #DISCOURSE_SMTP_PORT: 587
  #DISCOURSE_SMTP_USER_NAME: 365@domain.tld
  #DISCOURSE_SMTP_PASSWORD: ***

Guessing the reason for this different behavior may be that office365 does not verify the from: field when sending mail, but only rewrites the from: field to the username of the office365 account when sending mail, and QQ Exmail will verify the from field of the sent mail, while incorrect from: field could cause the 501 error mentioned above.

Topic		Replies	Views
Notifications incompatibles avec le reply by email Product Support	7	252	February 25, 2026
Issue configuring reply by email: 553 5.7.1 Sender address rejected: not owned by user Product Support	6	12907	June 13, 2019
How to setup "Reply by email address" now that it must be different from the "Notification email" Product Support	2	753	August 28, 2019
配置QQ邮箱发件，邮件正常到达，但是Discourse报错，会重复发送 Self-hosting	8	498	January 14, 2026
Gmail is using our notification email address, not the reply-to email Product Support email-in	2	174	August 9, 2025

Email Sending Issues Occured on Different Email Provider on notification_email and reply_by_email_addresses

Related topics