Undeliverable error message using Outlook

Garth13 · ‎2022-02-08

I have been using Microsoft Outlook and Shaw for 20 years on a PC without any issues.

My email seems to work fine except for when I send to a larger group of people (this is a new issue!). Quick background...every few days, I'll send an email to a group of people consisting of 15-20 email addresses (never had an issue...been doing this for years). This isn't spam or anything (just sending an email to players and coaches on a team that I head coach). Now as of this weekend, I'm getting an error message that says:

From: System Administrator

Subject: Undeliverable (...it shows my original subject line...)

Your message did not reach some or all of the intended recipients.

The following recipient(s) cannot be reached:

'xxxx.xxxxx@icloud.com' on 2/8/2022 9:18 AM

Server error: '450 HTAtnu1WAa4s1HTAtnEk81 internal error. AUP#SMTP'

The email goes on to list 10 email addresses. I'm assuming the email went through to the other emails that it didn't list. The list of addresses that it says it didn't reach included icloud.com, gmail.com, outlook.com, and a couple businesses. Not sure if it matters but I see it listed the same 10 email addresses in the last two times I received the error.

I called Shaw Technical Support. They said they can't provide any assistance on a third party app such as Outlook (but I don't think this is an Outlook issue as the email left Outlook and then had issues on Shaw's server?). They did confirm I wasn't anywhere close to my quota limit. They suggested I try using Shaw Webmail which I did and it seemed like the group email worked. However I really want to get Outlook working for me again. Anybody have any ideas?

In case it helps, here is some info on my system...

I'm using Microsoft Outlook 2010 on a Windows PC running Windows 10 version 21H2. (Windows Update says I'm up to date)

I haven't done any recent updates (to my knowledge) or changed settings.

When I go into Outlook settings, it says the following for Server Information:

Account Type: POP3

Incoming mail service: pop.shaw.ca

Outgoing mail server (SMTP): mail.shaw.ca

When I go into Advanced settings, I see the following server port numbers:

Incoming server (POP3): 110

Outgoing server (SMTP): 25

LoisM1 · ‎2022-02-10

Have you received any help with your problem. I have the exact same issue with Outlook/Shaw right now and it is a super drag as I communicate regularly with a group of volunteers in my community. Any assistance would be greatly appreciated!

Garth13 · ‎2022-02-10

I asked an IT friend. The first thing they asked me was "why am I still using POP3" as I guess it is old tech. I said I have no idea...just always been like that I guess. They encouraged me to switch to IMAP. Once I did that, it seemed to fix the problem. I could then send out my group emails without getting the undeliverable error message.

There are tips on the web about how to move from a POP3 account to an IMAP account. I got mine working for one day and now are having issues again as I think I messed it up (I can receive email but my sent mail appears to be trying to use the POP3 account which I deleted the email settings for...so now my sent mail gets stuck in my Outbox in the POP3 account).

debg1 · ‎2022-02-13

I'm also having the same problem with Outlook/Shaw in trying to correspond with a group of volunteers. At first I thought it was a file size problem with an attachment I was trying to send but now it's happening even without attachments. It's always the same 13 people of my group of 23 that show as 'undeliverable' Super annoying and need to figure out how to get this fixed. Any ideas would be appreciated

Garth13 · ‎2022-02-13

I think Shaw must have changed a setting or configuration on their side and that's why we're starting to see these issues. Anyways, switching to IMAP (which apparently is more common and newer than POP3) has solved it for me.

The other option you have is to work inside Shaw Webmail. I much prefer using Outlook but as an interim measure, that did allow me to send my group emails out without any errors. But I'm happy I switched over to IMAP as Outlook works fine again. Plus I think IMAP works better if you have multiple devices reading the same email account.

There are instructions on the web of how to switch over to IMAP but if I recall, I think I just did the following:

Made a copy of my PST file (and saved to another location just in case)
Added the new IMAP account in Outlook
I can't recall if I then deleted the POP3 account in Outlook at this time or if I first moved over all of my emails first

Anyways, I now just have the one email account in Outlook. However I do have two mail folders in the left pane of my Outlook (I think that means that I have two PST files in use). My old inbox, sent mail, and draft folders are still there under the old mail folder (the inbox and sent folders aren't doing anything so I guess I'll slowly go through those and delete the emails but the drafts folder is still the active drafts folder). I think I read somewhere that the PST file created for IMAP accounts doesn't have calendar and drafts so I think Outlook actually needs to run with two PST files now (your old POP3 PST file as well as the new IMAP PST file).

debg1 · ‎2022-02-14

Thank you! It's good to know there's a fix for this. I'll try switching over to IMAP and hopefully Outlook will still function since I'm not very tech savvy! 🙂

mdk · ‎2022-02-14

@Garth13 -- The following recipient(s) cannot be reached: 'xxxx.xxxxx@icloud.com' on 2/8/2022 9:18 AM

Server error: '450 HTAtnu1WAa4s1HTAtnEk81 internal error. AUP#SMTP'

AUP == Appropriate Usage Policy.

SMTP == Simple Mail Transfer Protocol.

Note that "icloud.com" is managed by Apple.

So, for some reason, Apple's SMTP-server thinks that E-mail from either your IP-address, or from the IP-address of Shaw's SMTP is to be blocked.

If you switch from using POP to using IMAP, you are sending from a different IP-address on Shaw's network.

So, while Apple is blocking one IP-address (POP), it is not blocking the other IP-address (IMAP).

Thus, switching is a "bypass" for your issue. It does not explain why Apple is blocking one of Shaw's IP-addresses.

EDIT: are those recipients that are "unreachable" all using ICLOUD E-mail IDs?

However, if there is a "black-list" of IP-addresses that Apple is using, it is probable that other ISPs are using the same "black-list", and may also be blocking your messages.

Mike205 · ‎2022-02-15

Has anyone found a fix to this? I called shaw and they outright refused to help.

Mike

mdk · ‎2022-02-15

@Mike205 -- Has anyone found a fix to this?

Can you supply more technical details:

IP-address that is shown when you access the www.who.is web-page. This will be the "public" IP-address that Shaw has assigned to your cable-modem.
What E-mail client are you using: Eudora, Outlook Express, Windows 10 Mail, Thunderbird, Microsoft Outlook ?
Are you using IMAP or POP settings within your E-mail client?
Within your E-mail client, have you configured your computer to use "smtp.shaw.ca" or "imap.shaw.ca" as the "outgoing mail-server" ?
What is the domain-name(s) of the ID(s) -- the part after the "@" in the E-mail IDs of the intended recipient(s) ?
What is the full text of the "rejection" E-mail -- more than just the one-line error-message?

With that information, we on this discussion forum can try to help.

Mike205 · ‎2022-02-15

Thank you Grand Master....let me see if I can provide the info you asked for...

First, some of my troubleshooting:

- this started (I think) on Feb 2nd 2022

- I use outlook on a windows PC

- I send email TO myself and BCC ~20 people, in an outlook Contact Group. Expanding the group doesn't seem to help.

- A buddy swears the issues is outlook and BCC

- I normally use POP3 (no sure why, I just always have)

Today I tested with POP3, IMAP and webmail.

POP3: everything fails

IMAP: some failures, some worked (one guy emailed me back, so I know one guy got the email)

webmail: everything (seems) to work

1. 50.71.21*.***

2. MS Outlook

3. POP

(see above)

4. type: pop3

Incoming: pop.shaw.ca

Outgoing: mail.shaw.ca

5. 6.

Your message did not reach some or all of the intended recipients.

Subject: ****** Friday

Sent: 2/15/2022 10:26 AM

The following recipient(s) cannot be reached:

'mike@shaw.ca' on 2/15/2022 10:28 AM