My guess is it's the IP address where the message originated (i.e. the public IP address of your router/gateway)  that is being blocked not the Media Temple address. To confirm, go to ping2me.com and compare the IP address displayed to the one in the NDR. If they match, you'll need to contact your ISP to have them help address the problem. If the ISP's address is being black-listed, Google is likely blocking it as well.

It would be easier to get your own Hotmail or Gmail account.  They're still free.

From your OP, I'm assuming you are using a mail client on your PC rather than your web browser to access your mailbox. Does your Media Temple mailbox allow web access as with gmail and hotmail? If so, log into the portal and try sending your sister a message from there. The message header will show the message originating from their IP address instead of yours and, if it goes through, you'll have solid evidence that the IP address assigned to your router/gateway by your ISP is being black-listed. Even if you are able to work around the problem, it's worth bringing to the attention of your ISP. You should also check you PC for spambot malware.

Well, my response is a mix.  Firt, Dave, I host about a dozen email addresses (family-owned URL, three different business URLs, etc) so just stopping using the email addresses we have used for years is not an option.

Interesting info Gilnov.  I did log into web mail and sent an email to the Hotmail address and did not get a bounce back.  However the IP address quoted in the bounce back messages does not match my IP address, so still seems to be a Media Temple issue.  My ISP is Comcast.  And the situation is a bit different than I described.  The hotmail account is owned by my sister's daughter, and my sister also cannot send email to her daughter; I host my sister's domain under my MT account.  I have tried sending from four of my other email accounts, and they all bounce, and are all hosted by MT.

It would be useful to see the NDR so we can see where things go awry. If you can PM it to me, I'll be happy to take a look.

Oh, and as for the IP address not matching, if you don't have a static IP address, it is possible you have a different one at random intervals. The fact you didn't get a bounce when sending from the browser supports the notion that the problem is the Comcast IP address at your physical location. Often, ISP's will assign a block of addresses to a building of neighborhood and the whole block of addresses will be black listed because it is impossible to tell which address within the range spam is coming from. IOW, you may be guilty by association because of the activities of a neighbor.

Check your IP/domain name here to see if it is blacklisted: https://mxtoolbox.com/blacklists.aspx

If so, you can check with each organization that has listed you to see why and that may provide more clues about what's happening.

I assume that my IP address, etc, it circulated everywhere, so not a risk to publish them.  My location IP address is 24.4.202.105.  The address quoted in the bounce backs, which I assume to be Media Temple, is 216.70.64.149.

I checked both with your Blacklist tool, with this result:

My IP:
  Spam cannibal
  Sorbs Spam

MT IP:
  Protected sky
  Sorbs Duhl
  Spamhouse ZEN

But to get back to my original post, wouldn't switching to the Google SMTP fix this?  I suppose a block of Google IP could also be blacklisted, but would be worth a try.

For a bit more perspective:  I send my niece an email every few months, but her mother does so daily.  So I'm trying to fix it for her.  I have remote control of my sister's PC, so could check her IP address for blacklisting too, but I am in California on Comcast and she is in Missouri on Charter so the only thing common here is both of our email URLs are hosted by Media Temple.

The message headers will still bear your IP address as the originating "server" (your mail client is essentially a mail server from the internet's point of view) so if that IP is blocked at the recipient (or any server along the path), it will be rejected. Setting up google in your mail client will change the path your messages take but not the point of origin. From the above results, it appears both your ISP IP address and the MT address are on multiple lists. I need to tend to some other things at my actual job right now but I'll do a little digging later today and see what I learn.

I don't think you can use Gmail SMTP without a Gmail account.  Even then, you may have to have a Gmail business account to send multiple email addresses thru it.

If you're on Comcast, then you should have a Comcast email address also.  Do you have any problems using it?

I looked up your IP address (24.4.202.105) here: http://www.tcpiputils.com/

Then scrolled down to the "SPAM Database Lookup" section. It says there are 10 spam hosts in the 24.0.0.0/12 address block which comprises 2 to the power of 20 potential IP addresses. That's over a million IP addresses. It looks like a few bad actors are spoiling it for a lot of users via guilt by association.

As I said earlier, there is no way from the outside to tell which of the one million-plus addresses are spamming so the only way for mail sites like hotmail, gmail, etc. to combat the problem is to block the whole range until the service provider (Comcast) takes action. Only Comcast is in a position to identify the source IP's within the million address block.

But there's more....

If you follow the link next to where it says "SPAM Tools", it checks your address against a long list of anti-spam organizations (folks that maintain blacklists - there are hundreds and they come and go frequently). Next, click on the link labeled "pbl.spamhaus.org" in the resulting table (it says "LISTED" with a red X) then click "PBL1522993" and you'll see this message:


Take a look at that page linked in the above message and confirm that your email client is properly configured. If it is, let Comcast know about the problem so they can take action. Although, if 1 million addresses are affected, I'm sure they are aware already...but why leave it up to someone else?

I do have a Gmail account; in fact about 20.  Long story.  But they are fast and easy to get, so would not be a problem to have have one per my regular email accounts.  Yes I have a Comcast email, but never use it.  Let me dig up the credentials and give that a try.

I use Thunderbird.  I have never used Outlook Express (I thought uSoft killed that years ago) and have not even had Outlook installed for maybe ten years.

I use Thunderbird both thru Comcast and with a Comcast email address.  If all of your people are connecting thru Comcast, that might be a better way to go.  I know that on Residential connections, Comcast blocks port 25 which used to be for connecting to mail servers.  Those instructions look right except that I use POP3 instead of IMAP.

So, I set up my Comcast email using Thunderbird, and successfully sent to the hotmail account.  I have set the Comcast STMP as the default, such that all of my email accounts are using the hotmail SMTP path, and they all seem to be working.  I just want to make sure Comcast doesn't notice some time later and object.  Any idea if this is OK with Comcast?  I would call tech support and ask, but expect either the question would not be understood or that the answer I got was one I could rely upon.

I can't say for certain but, since they let you set up all the accounts, it's probably fine. I have had multiple mailboxes set up on my residential Comcast account for many years without issue. I haven't looked in years but I don't remember there being any limits. Maybe storage space or bandwidth but not number of mailboxes.

Well, never figured out Google's SMTP, but as always "Anything you can do is better than anything you can't do", so thanks for the help.  If someone stumbles into this posting also trying to get Google SMTP going, the short answer is "Try using the SMTP of your ISP if you are hosting your own email server."