Newsletter: Mail delivery failed: returning message to sender

[tabata]

Hi!
We must send an email to 700 contacts.
But 40 email don't delivery with this error:

This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

But if we send an email to contact individually, this is sent! Why?


sorry for my english...

[cPanelDon]

What method was used to send to "700" contacts at once?

What method was used to test each failed address; was it the same method used to e-mail all 700 contacts?

I would check the Exim mail server log for more specific details while the deliveries are being attempted to determine more specific information. The following command (via root SSH access) can be used to monitor the Exim main log for relevant data:

# tail -fvn0 /var/log/exim_mainlog

[cPanelDon]

I've relocated the thread into the Mail forums so it may receive more relevant discussion and attention around similar topics.

[tabata]

What method was used to send to "700" contacts at once?

What method was used to test each failed address; was it the same method used to e-mail all 700 contacts?

I would check the Exim mail server log for more specific details while the deliveries are being attempted to determine more specific information. The following command (via root SSH access) can be used to monitor the Exim main log for relevant data:

# tail -fvn0 /var/log/exim_mainlog

Hi!
we always send email with outlook.
If we send an email only to the 40 contacts individually, that is delivery. (with outlook)

[cPanelDon]

Hi!
we always send email with outlook.
If we send an email only to the 40 contacts individually, that is delivery. (with outlook)

What error details are seen in the returned e-mail bounce messages?

Is SMTP authentication enabled in Outlook (where Outlook is set to "login" to the e-mail account when sending)?

[tabata]

Subject: Mail delivery failed: returning message to sender

This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:
...
...
------ This is a copy of the message, including all the headers. ------
------ The body of the message is 360566 characters long; only the first
------ 106496 or so are included here.
...
...

The SMTP authentication isn't enabled.
We use the POP3 Access (SSL)

[Infopro]

The SMTP authentication isn't enabled.
We use the POP3 Access (SSL)

In Outlook go to where you setup your email accounts, select the one you use to send the email and click edit. Find the "More Settings" button and click. Find the Outgoing Server tab at top and click. On this page tick the "My Outgoing Server (SMTP) Requires Authentication" and, "Use same settings as my incoming mail server" Save and close.

Assuming you are sending this email directly to all 700 users, and not thru a mail list setup on cPanel in advance, you might make sure you're using BCC. Having them all on a mailman list in cPanel would be a better way to go though, as the system can be configured to drop dead emails. You send one email to the server, it sends out 700 emails to the email list, and drops the dead emails that no longer work.

[cPanelDon]

The SMTP authentication isn't enabled.
We use the POP3 Access (SSL)

As Infopro detailed, please ensure that SMTP authentication is enabled in Outlook; this will help ensure your e-mail client (Outlook) is properly logged-in to send e-mail.

It may also help to ensure that your domain has both SPF and DomainKeys enabled via cPanel, to help reduce Spam and increase chances for successful delivery:
EmailAuthentication < AllDocumentation/CpanelDocs < TWiki

I believe it is a good idea to consider another, more reliable method to send to a large recipient list, preferably from a server-side mailing list daemon like Mailman; this will centralize subscribing and unsubscribing users, and also allow users to optionally subscribe or request to subscribe, or unsubscribe independently if needed; using Mailman will also offer greater control in managing the list by having it located on the same system as cPanel.

The following documentation details the Mailman-specific features in cPanel, including how to create a mailman mailing list:
MailingLists < AllDocumentation/CpanelDocs < TWiki

For additional reference, I recommend searching and reading through the official Mailman wiki, FAQ, and documentation resources; for your convenience, you may find the links to these resources below:
Mailman Features
Mailman Documentation
Mailman Frequently Asked Questions
Mailman mailing lists
Mailman Wiki
mailman-users