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dpastern
Contributor
Contributor

Re: SMTP problems

Oh, and I meant to add that my Optus address has probably been deleted when my original NBN connection was cancelled.  Long story short:

 

i) had Optus NBN at residence

 

ii) my mum passed away and house was left to myself and my sister

 

iii) sister and her partner moved in.  

 

iv) my NBN was cancelled and my brother in law's NBN connection/account was migrated from their old street address to the current residence

 

I do not know if my brother in law has been given a @OPTUSNET.com.au Email address or not, but will check.  At this point of time, I am uable to test from the Optus web portal.  I'm just waiting for my brother in law to get home from work.  edit: my brother in law does not believe that they were offered any @optusnet.com.au Email addresses when they got their account set up.  

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dpastern
Contributor
Contributor

Re: SMTP problems

Just an update:

 

Issue is still persistent, both on Optus NBN (home) and Optus 4G (outside of home network).  

 

PM sent to GuyCS asking for a ticket to be logged with the appropriate technical support team.  

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UncleB
New Contributor
New Contributor

Re: SMTP problems

I've been having the same problem since the start of the month. It's causing me work issues seince I now can't send invoices to my main employer. I'm afraid I didn't understand much of the above conversation but surely there is a straightforward fix for this. Seems ridiculous.

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dpastern
Contributor
Contributor

Re: SMTP problems

Hang in there UncleB - Optus are aware of the issue and a support ticket has been opened.  

 

I missed a vital thing in my troubleshooting - the IP address of Optus' SMTP mail server (as it's hidden by default).  I realised that I'd missed checking this earlier today, and sure enough, when I looked at the raw message data, and checked the Optus IP address, it's blacklisted on a RBL (Real-time Blacklist).  

 

Optus will need to organise to de-list their IP address(es) from the relevant RBLs, and then things will return to normal.  

 

What typically happen is that there are thousands and thousands of people using Optus' SMTP server to send Emails.  Someone, on an Optus Internet connection has spun up their own mail server, and routed mail out via Optus' network, but haven't secured their mail server.  It got hacked, and spammers spammed out lots of Emails from their hacked mail server.  It happens quite a fair bit.  It could also be caused by someone's PC being infected with a virus and mailing out spam from their computer.  

 

It'll get fixed, but may take a few days through to a week or so to sort out (some RBLs are really hard to de-list from, especially one called SORBS).  

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Dan_C
Retired Employee
Retired Employee

Re: SMTP problems

I've checked the ticket that's been raised - 20033601.

 

There's been 10 or so updates today.

 

I'll continue to monitor and send out an update once we have more information. 

 

 

 

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dpastern
Contributor
Contributor

Re: SMTP problems

Thanks Dan!

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Marliu
Occasional Contributor
Occasional Contributor

Re: SMTP problems

I've been following your thread with interest as I've had issues with sending to Yahoo since 7/11/18. Chatting online with Optus has proven futile as no one seems to be able to provide any answers and last week was told to contact Yahoo help desk as it wasn't their problem! (It's only this week that Optus seems to be admitting that the fault might be at their end). Just letting you know also that when I send email to Yahoo addresses, it bounces back after 5 days! Is this usual? And I've tested sending to my own Yahoo account about ten times...mail got through a couple of times, the rest bounced. Doesn't matter if I'm using Outlook from my desktop or if I'm sending directly from Optus Webmail, emails aren't being delivered to Yahoo. I also have similar issues sending to my AOL acoount. Gmail addresses works for me so far although I've heard that this may be affected for other users. Even though I don't understand most of the technical jargon, it has shed more light than chatting with Optus online! Thank you!

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dpastern
Contributor
Contributor

Re: SMTP problems

I uderstand your frustration.  My experiences in the industry have led me to believe that the vast majoriy of level 1 techs do NOT understand how mail works.  Because of this, incorrect information is frequent and rife.  The number of times I've had a cusrtomer @ my last job say "but I can't send my ECN Email from my mobile phone" (using Bigpond 4G)...they'd been told that they MUST use ECN's SMTP servers "cos it's an ECN Email address".  Wrong, wrong wrong.  SMTP is *always* (with One caveat which doesn't really need to be mentiond) handled by your ISP.  

 

The bounce backs (aka fialure notices) are normal.  What typically happens is that a SMTP mail server will try and send mail X amount of times (this is configured by whoever set the SMTP mail server up, and CAN, and DOES, vary from server to server, there is no One default).  From my experiencs, mail servers typically try to send mail for 3 days - that seems to be the most common setup.  If the SMTP mail server cannot connect to the foreign mail server (aka destination mail server), it will re-try at specified intervals.  Once the X amount of days are up, it gives up and generates a failure notice back to the recipient.  This is what you are seeing.  I too am getting these failure notices, although I didn't read the entirety of the data (my mistake!) as I was viewing them via a webmail setup, and it obfuscates some of the critical data.  I'm getting old and rusty lol!  

 

Mail servers subscribe to things called "RBLs" (Real-time Black Lists).  Basically, RBLs are independent servers, that are designed to catch SPAM (they are technically called honeypots).  This allows these RBL servers to work out which mail servers globally are spamming.  If a mail server is spanming beyond a certain point, it gets listed as a troublesome spamming server.  There are hundreds of RBL servers, if not thousands, and when you set up a mail server, you'll usually pick 2 or 3 to subscribe to, to help filter out SPAM.  If your mail server blocks ALL mail from a known SMTP server sending out SPAM, you cut down on a) Internt traffic and b) (and more importantly), SPAM.  No on likes SPAM.  We want HAM.  More on this in a bit.  What you'll find is that both AOL and Yahoo are probably using the same RBL to reduce SPAM traffic to their mail server(s) and Optus' SMTP server is listed and therefore blocked.  Basically, ALL mail from Optus SMTP server(s) will be ignored (not to be confused with all mail from optusnet.com.au - i could be using an ECN Internet connection to send mail outwards...).  

 

There are ways to help reduce spam such as SPF (Sender Policy Framework) records in the DNS zone file for your domain.  These can lock down which IP addresses (Email servers) can send out mail on your behalf.  The problem is that many people who set up DNS, do NOT set up SPF records, or set them up correctly.  You can use online tools such as https://www.kitterman.com/spf/validate.html to check the syntax of your SPF entry to make sure that it's correct.  An alternatwive is DKIM (Domain Key Identified mail).  I prefer SPF over DKIM, but that's a personal thing.  Both anti-SPAM methods do work and help reduce SPAM traffic.  

 

Now for some joviality, the origins of SPAM, a Monty Python skit (yes, really!):

 

https://www.youtube.com/watch?v=anwy2MPT5RE

 

Cheeers!

 

 

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Marliu
Occasional Contributor
Occasional Contributor

Re: SMTP problems

Hi dpastern

Thanks for the feedback! All makes sense although my understanding of DNS, SPF, DKIM is vague and I wouldn't know where to begin to check if my SPF/DKIM is correct. I'll just have to look on the bright side and watch some Monty Python...

dpastern
Contributor
Contributor

Re: SMTP problems

SPF/DKIM is done at the domain level.  Unless you own a domain, there's no real need for an ordinary user to be concerned with them.  I simply mentioned them as an aside to give the general populace an idea on how SPAM is combated.  The differences in the methods are that SPF and DMIK are both proposed standards, with RFCs, RBLS are NOT.  I have long disliked RBLs and their methods of operation.  As I've said a few times, they are nothing but vigilantes, holding themselves above the law.  It doesn't help that in a few legal cases of ISPs vs RBLs in the US, the RBLs have prevailed, much to my disgust.  But hey, it only shows how broken the judicial system is!

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