Inconsistent send from Outlook

[Genghis the Engineer]

Anybody got a clue on this one?

My main personal email is a .flyer.co.uk account run off Outlook on my laptop.

I routinely connect my laptop to the web by one of the following four routes:

(1) Home Wifi, which is a wireless router on Plusnet
(2) Work Wifi, which is a wireless router on BTIntersomethingorother
(3) My phone, an HTC Wildfire on 3 with a Wifi hotspot mode
(4) Second office, on a university campus, with an academic Wifi login.


All four I can access the web fine, all four I can download emails fine, or use webmail.

(1) and (2) I can send emails from Outlook as well.

(3) and (4) I cannot send emails from Outlook: if sending an email becomes necessary I either need to log into webmail, or go home!

Has anybody any idea why this problem exists, and can you offer any possible fixes?

G

[Mike-Bracknell]

It's by design, so that you don't go flooding the internet with spam and are forced to use the ISP's SMTP server instead (where they have control of whether you spam people or not).

[Airborne Aircrew]

It is possible that 3 and 4 are blocking port 25, (SMTP), which is what outgoing mail uses to prevent spambots. In general administrators will configure their firewalls to only allow bone fide mail servers to use SMTP on port 25.

[Genghis the Engineer]

So not a lot that I can do about it then?
G

[Capetonian]

I've configured my laptop to use port 587 and it works wherever I am in the world.

[Airborne Aircrew]

Cape:

Sneaky... But the server admin and the firewall admin have to "be in on it".

[Capetonian]

I don't know,Airborne Aircrew but it's what an incredibly helpful call centre agent told me at the Indian support centre. It worked, so I'm happy to share it with anyone who wants to try it.

[Airborne Aircrew]

I looked into it and yes you're call center chap is spot on. But most mail servers do not come configured to receive mail on that port and have to be set to allow it and the firewall admin, (could be the same chap), would have to open the port on the firewall so that any external IP can reach that port on the mail server. But yes, it's all very viable. Who on earth did you call that had a call center wallah that well informed????

[Genghis the Engineer]

Originally Posted by Capetonian

I don't know,Airborne Aircrew but it's what an incredibly helpful call centre agent told me at the Indian support centre. It worked, so I'm happy to share it with anyone who wants to try it.

Pretty please yes.

G

[Saab Dastard]

Good, readable wikipedia entry for SMTP here:
Simple Mail Transfer Protocol - Wikipedia, the free encyclopedia

Refer particularly to the Outgoing mail SMTP server section.

SD

[BOAC]

Pretty please yes.

- I think he already has

Confused about 3) - you are using Outlook on an HTC mobile? Why not just use the normal HTC outgoing mail sender and fiddle around with the authentication settings - you will find that 587 'pops up' for some settings - and works!

[Genghis the Engineer]

I work hard at being a computer ignoramus these days - maintaining that officially I'm only paid to be clever about aeroplanes. Many years ago I was writing 1000++ lines of code in Fortran or Pascal for things like machine control or CFD analysis, and published a computer game (Zombie Island for the ZX81 if anybody remembers it) and a very dull CBT package called "Fatigue Crack Growth". Then I got properly and sensibly obsessed with aeroplanes, put my computer in the same category as my slide rule and propelling chinagraph as useful tools only, and have felt much better since.

However, I'm on top of things enough to be able to say that I'm not using Outlook on my HTC mobile - I'm using Outlook on my Toshiba Portege; I'm using my HTC mobile as a Wifi hotspot.

I shall go and read the Wikipedia stuff and see if I can understand it and work out how to make that work. Thanks chaps.

Cheers,

G

[BOAC]

I'm using my HTC mobile as a Wifi hotspot.

- sorry - mis-read your OP. It is quite common for a hotspot to block 25, so I suggest you try 587 but you will probably need to set up authentication on the outgoing emails.

The campus problem may be the same as a Scandi hotel I used to use - outgoing would only go via the smtp server for the hotel.

[Gertrude the Wombat]

It's by design, so that you don't go flooding the internet with spam and are forced to use the ISP's SMTP server instead (where they have control of whether you spam people or not).

Really it's daft to block you from using port 25 to send email via your own server which requires authentication but that's what some WiFi ISPs seem to do.

The solution is to play hide-and-seek with different port numbers.

Find a port other than 25 on which your SMTP server will play and use that, and hope that the WiFi ISPs don't spot people doing that and block that one too.

[BOAC]

To add - if GTE wishes to check, from a cmd prompt

telnet my-domain-name.com 25

[Mike-Bracknell]

Originally Posted by Gertrude the Wombat

Really it's daft to block you from using port 25 to send email via your own server which requires authentication but that's what some WiFi ISPs seem to do.

You assume wrong. The reason they block port 25 is because that's the traditional SMTP server-to-server port which spambots use to brute-force send to other SMTP servers, that don't require authentication for company-to-company email traffic (for obvious reasons). If they allowed that to happen, their own IP address ranges get marked as spamming and that negatively affects the reputation for the legitimate email traffic.

i.e. it's not as daft as you think.

[ExSp33db1rd]

Don't understand a word of it, but I do know that I can take my laptop to the Public Library when I visit the USA, and see everything except my Outlook Express, so I can't download from my NZ ISP webmail to the laptop to read Offline when I get back to the apartment, I have to read and reply on the Webmail in the hour per day I'm allowed to use the service.

I complained and was told that it was deliberate, 3rd party e-mail accounts - they said - were deliberately blocked to protect from Spammers and Porn.

Makes sense I guess, and would have tried to get around it, but have discovered that if I sit outside Starbucks around the corner, I not only don't have to buy their coffee, their free WiFi connection allows me to use Outlook Express without any trouble.

[mixture]

Really it's daft to block you from using port 25 to send email via your own server which requires authentication but that's what some WiFi ISPs seem to do.

Find a port other than 25 on which your SMTP server will play and use that, and hope that the WiFi ISPs don't spot people doing that and block that one too.

I'm not going to repeat what Mike said.

What's "really daft" is to run your own SMTP server when you really don't need to, and when you don't understand the reasons for anti-spam measures and how these can be legitimately bypassed if you need to.

Basically, what I'm trying to say is :

- If you're a private individual (or a one-man business) then there is really no need to run your own SMTP server. There are many other ways to achieve what you need without the headache (e.g. "smtp.com" and other similar services).

- If you're a business, then you probably ought to look at changing IT providers if they can't figure out a way to give you roaming email (or just moan loudly at your IT department in larger companies).

[Stu666]

Sometimes if you inform your ISP that you are hosting your own email server they will allow you to use their smart host server hence unblocking port 25. I have done it with BT and O2 to successfully host Exchange servers on domestic broadband packages.