The problem with that is when you get a mobile phone, and a laptop and desktop at home, then it has traditionally been an issue as the ISPs themselves have failed to let authenticated mail be sent if you aren't on their domain as isp. ISPs are reaping what they have sown. If they actually had let authenticated mail be sent through their servers, even if your device was connected to another isp at the time then half the messed up work arounds we used over the last 10 years would have been null and void.
Any authenticated mail cases are null in void when the recommended settings are used. There is no reason in this day in time that you should use a relay service, That is going to cause issues soon as you visit a friends, Change providers etc.
Using SSL configurations allows you to skip all the hassle and have your security, No work around just looking forward to where things should be at these days..
Xtra were quicker off the mark with authenticated SMTP than most but then botched that with port 25 blocking and a raft of other idiot processes banning emails until you filled out impossible to find forms they then ignored.
Spark make port 25 unblocks easily found..
Search will also bring this up straight away, I can't speak for other ISP's
Vodafone / Clear / Paradise - probably the very worst. Still no authenticated smtp for clear last time I checked and I think paradise ditto. Trying to use vodafone authenticated smtp was a failure in the making if you were a clear or paradise client so thus loose spf records allowing you to send from other ISPs / anywhere becuase at the end of the day you arent allowed to put in enough isp names and ip addresses in an spf to cover all of NZs offerings.
I still wince at the number of mail servers we had on telecom / xtra networks where the client connected to them as the single point of authenticated mail sending, using anything other than port 25 / 26 and the support issues that raised. Then having to smart mail them through xtras smtp or send.xtra.co.nz as the sillybuggers blocked sending ports on their networks.
Filtering port 25 by default is normal these days, i dont exactly understand why you look at this as playing silly buggers.
Vodafones support for email service is absolutely the bane of my existence at this time, 95% of the cases i deal with on this issue, Are Vodafone based services.
Vodafone do have an option for their paradise servers to add /p to the front of your username to be able to authenticate externally But this is not sparks job to setup Vodafone customers emails correctly.
Vodafone unfortunately do a horrible job at supporting customers through this process aswell, the lack of SSL support on many of their platforms and janky workarounds such as /p adds to the frustration.
Vodafone will not take ownership of this for customers and pass the blame, when technically it is Their product that is not working correctly.
Again - the ISPs are their own worst enemies.
I always said I would never run commercial mail servers but now have three as it is still less painful to take that responsibility than deal with the crap using ISPs email has caused. Uptimes all reflect we only reboot once a year on some of the servers to get windows processes to pick up the renewed certificates. Happy clients. Happy IT guy.
I'm glad you keep your clients off ISP provided services, Business's should be on Business grade email address's.
The amount of business's that i deal with who have xtra email address's is astonishing.
I will say at this point, the issues with Authenticated email address's do seem resolved, There is a few edge cases however spark have a special back-end team who is going through double checking these cases and returning to be followed up.
The one case where this still will not work, Is clients that are unsupported by sparks network - EG Outlook Express does not support the SSL requirements.
Re port 25 blocking. Over the years we have had a number of clients who ran their own exchange server and their ISP was Spark / Xtra. Exchange gives calendar, push notifications etc. Unfortunately when the exchange server goes to send to another mail server the port 25 blocking rules would stop it being able to send out.
Yes, you can apply for that to be removed on your static IP address but the forms are arcane, most of the questions make no sense as they didn't apply, the response was slow and the chances of them getting it right were very hit and miss. Then they would reverse the policy. if I charged for all the time spent on phone to xtra on mail issues me and Bill Gates would be dining out in the same clubs.
The answer was often have your exchange server upload mail to sparks smtp server as a smart relay - with other attendant issues like getting blocked as xtra were black listed. The other issues faced included getting dropped as spam as even static ip address ranges were registered by telecom / xtra / spark with black lists as not allowed to host mail servers - so by sending direct from your static IP address you got blocked via black lists. We did also use thirdparty mail box as collection point then pulled it down to the exchange server - but then splitting out mail at that point had its hiccups requiring third party add ins or mail pull servcies to munge te addres into the right boxes. Exchange etc was never good at pulling from a global pop collection box.
Again - my comment was on the historical mess that has left us in the situation we face today and forced so many hacks and work arounds to deal with stuff.
Our clients mostly use mail servers hosted by NON ISPs that specialize in mail services ( digiweb were a good go to for many years - great support until they got bought out) or mail servers we run on VDS / VPS on their behalf. however, it is only in recent years that the cost of data and VPS and cloud services have got to the point that not having to hack your way through the ISP induced mess was financially reasonable.