benhelps
Level 8: Inspector

smtp.telstra.com:25

Not sure which category this most correctly belongs in, so putting it here.

/paste follows

 

Wow. Just, wow. They so willfully misunderstand the problem they are
assured the problem is not theirs and that we need to talk to
"Cloud Lay" [sic] (Cloud Flare) who I have our DNS for our domains
set up on.
And who have nothing to do with the problem.
And who I've not made any relevant changes on in weeks.
We have an on premise Exchange mail server that receives all our mail.
It works fine.
All our office mail clients use smtp.telstra.com:25 to send mail
(not our Exchange server; inherited oddity). Until 201805160900 it was
working fine; a little after that (by 09:45) smtp.telstra.com:25 was
returning 558 OB703 errors whenever we tried sending mail.
Any mail.
To anyone.
Oh, also there had been no changes made to our Exchange server (or anywhere
on our network) - I'd be the only one making changes.
Yes, our mail server is not showing up as an open relay (it isn't one).
No, neither spamhaus (or any of another 93 similar services) are showing
our mail server's IP as blacklisted.
No, we don't have viruses, trojans, etc (malware) inhouse (according to the
latest scans by MS Defender, Trend Micro, Malware Bytes and others).
I'm just trying to answer the likely first questions/suggestions with what
we know/have already tried.
Also side note, since then I've tweaked our Exchange server (disabling
certain IPv6 settings) such that our Exchange server *appears* to be fine
for sending (will await any remote server bounce messages).
Still.

Ben Helps
https://benhelps.me

Was this helpful?

  • Yes it was, thank you
  • No, I still need help
14 REPLIES 14
benhelps
Level 8: Inspector

Re: smtp.telstra.com:25

Do I hear crickets?
Ben Helps
https://benhelps.me
Wizard2
Level 7: Deputy Inspector

Re: smtp.telstra.com:25

OB703 errors are normally due to the server or another service like Spamhaus rejecting the outgoing email (because of the PBL list).

Are you using a hosted email address or a BigPond Email address to send emails? If you're using a BigPond email address, turn on outgoing authentication and set it to port 465. However if you're using a hosted email account, Use Port 465 with authentication off and see if it works. If it doesn't though, you're out of luck and will need to configure an authenticating BigPond account. Make sure to set the reply email address to the one of your choice to make sure it comes back to your preferred email account and not your BigPond account.
The internet is a wonderful place.

I am a Telstra Employee however i am posting in my own time. My opinions are my own and not that of Telstras. I am a customer of Telstra.
benhelps
Level 8: Inspector

Re: smtp.telstra.com:25

We host our own mail for our own domains on an on premise Exchange server. We simply use (and have without issue for the last decade) smtp.Telstra.com:25 (with no auth) to send mails. As of the date time mentioned above that stopped being the case, despite the lack of spamhaus or other blacklisting, despite current scans of office requirement coming back clean, and despite changes to what is sent, or to who.

As outbound email is a critical component of any business, I've gotten our Exchange server sending directly, though it is SLOW
Ben Helps
https://benhelps.me
Telstra Platinum
Telstra Platinum

Re: smtp.telstra.com:25

Hi benhelps,

have you tried to use port 456 and authentication? How did that work?

-Ern

Telstra Platinum Tech Support


Icon image for Telstra Platinum

---------------------------------------
I am a Telstra Platinum employee and I do phone support for all issues like this one here.
Want one of our Telstra Platinum experts to solve this problem for you? One call to Telstra Platinum could help you with similar tech issues rather than trying to do it yourself. Click through to learn more about Telstra Platinum

Telstra Platinum

benhelps
Level 8: Inspector

Re: smtp.telstra.com:25

Well I'd need to know what authentication to put in, given we don't have/use bigpond to the best of my knowledge (we do use Telstra for ISDN landlines and NBN I believe).
Ben Helps
https://benhelps.me
Wizard2
Level 7: Deputy Inspector

Re: smtp.telstra.com:25

It seems you have not fully read my last reply.

TL;DR Use Port 465 with authentication off and see if it works. If it doesn't though, you will need to configure an authenticating Telstra BigPond account. If you don't have one, the Business tech support team can assist with getting one for you.

The internet is a wonderful place.

I am a Telstra Employee however i am posting in my own time. My opinions are my own and not that of Telstras. I am a customer of Telstra.
Level 24: Supreme Being
Level 24: Supreme Being

Re: smtp.telstra.com:25


@benhelps wrote:

All our office mail clients use smtp.telstra.com:25 to send mail
(not our Exchange server; inherited oddity). Until 201805160900 it was
working fine; a little after that (by 09:45) smtp.telstra.com:25 was
returning 558 OB703 errors whenever we tried sending mail.
Any mail.
To anyone.


Curious as to why you're using smtp.telstra.com on 25 for your outgoing mail? Could potentially be part of the reason why it got flagged. What type of Telstra internet service do you have? AFAIK that smtp server is for consumer and customers on Telstra business connections get a different one to use

 

Have you sent an email to the postmaster? Details on what to include are outlined Here

 

 

I am a Premium Services Support Consultant (Telstra Platinum, Telstra Smart Home, Locator/Device Locator and Neto POS). However, I am not an official representative on CrowdSupport.

IT Helpdesk and Technicial Support by Telstra Platinum
Smart Home Automation & Monitoring from Telstra
Helping Australians Find the Things that Matter Most with Telstra Locator
Run a Modern Retail Business with Neto Point of Sale
benhelps
Level 8: Inspector

Re: smtp.telstra.com:25

As I mentioned, the fact we've been successfully using exactly that setup is an inherited oddity. I believe in the dim past our Exchange server was deemed inadequate to send out marketing mass mails to our lists. We've long since been using cloud based mass mail senders but still use smtp.Telstra.com:25 for our normal daily emails out to customers, vendors, etc. We used to be on Telstra ADSL2 and for months now we've been transitioned to Telstra FTTN NBN (Telstra still haven't provided us a business grade modem for our business plan, but that's a different story)
Ben Helps
https://benhelps.me
Level 21: Augmented

Re: smtp.telstra.com:25

Your set up is rather weird... If I was Telstra, I would be blocking you too...
DISCLAIMER: I do not work for Telstra or any other ISP. I never did. I have wealth of practical knowledge in Computer Security and Forensic Computing. I have been in the field since 1985.

Likes (formerly Kudos) and solutions are appreciated!!!
The comments expressed by me reflect my user experience and personal opinion.
Level 24: Supreme Being
Level 24: Supreme Being

Re: smtp.telstra.com:25

Not exactly. It may of taken a while (series of flags), or something in particular done just prior to the blocking, for the system to block it. I'm not completely familiar with what processes mail goes through to result in a spam block

I was under the impression business's are usually given smtp.telstrabusiness.com to use for outgoing mail. smtp.telstra.com is the consumer version, and generally has more stringent rules in place in regards to outgoing mail. Using 25 on it (which is not recommended) probably played some part overall. It may pay to speak to DoT or Telstra Business and find out what the recommended outgoing server details are
I am a Premium Services Support Consultant (Telstra Platinum, Telstra Smart Home, Locator/Device Locator and Neto POS). However, I am not an official representative on CrowdSupport.

IT Helpdesk and Technicial Support by Telstra Platinum
Smart Home Automation & Monitoring from Telstra
Helping Australians Find the Things that Matter Most with Telstra Locator
Run a Modern Retail Business with Neto Point of Sale
Technical Support
Technical Support

Re: smtp.telstra.com:25

If your service is now with Telstra Business, this guide may be helpful as it offers a variety of different server configurations for Telstra Business customers, that you may find work for your "inherited oddity" 

Need help? Check out our Community Wiki or Support Portal || Looking for a new mobile? Order online today || Get help with any Tech at Home with Telstra Platinum || Don't forget to tag answers as Accepted Solutions and give a Like to the member(s) who helped you out.

All moderation actions are supported by the CrowdSupport Community Guidelines

benhelps
Level 8: Inspector

Re: smtp.telstra.com:25

Yeh if our Exchange server proves to unreliable at sending I may have to chase Telstra up. I'd also tried smtp.Telstra business.com:25 with no auth (as we've been successfully ding for many years) but it failed with the same error.

And not sure about accumulated block signals finally hitting a threshold, but the blacklist given to me by Telstra themselves to check (spamhaus) reports us as clean, as do all other blacklists on MX toolbox.
Ben Helps
https://benhelps.me
Technical Support
Technical Support

Re: smtp.telstra.com:25

We also have other tools that we use to fight spam. Did you follow the suggestion from Yas, to send the details to the postmaster? - Shelly

Need help? Check out our Community Wiki or Support Portal || Looking for a new mobile? Order online today || Get help with any Tech at Home with Telstra Platinum || Don't forget to tag answers as Accepted Solutions and give a Like to the member(s) who helped you out.

All moderation actions are supported by the CrowdSupport Community Guidelines

benhelps
Level 8: Inspector

Re: smtp.telstra.com:25

As mentioned before, we're currently using the Exchange server itself to handle sending. So if that proves inadequate I'll gather all the data to send to postmaster.
Ben Helps
https://benhelps.me

Goodbye Excess Data Charges

Hello New Plans.

Find out more