Smtp Server Error



I work for a web design company and have setup a new site and hence some email. My client has a brand new Mac OS X and am trying to help them setup their email using "Mail". I have setup the pop account and all works fine as I have done this many times.
However when we setup mail there is always a problem with sending mail and the SMTP settings.

We are both using the same ISP and we have never had a problem before. I setup using my Mac on our network their email account and it worked fine and I could email anyone. However when I repeat exactly the same settings we get this SMTP error. I can ping the server fine which suggests a firewall is not blocking it.

To test the software in case it was an error with "Mail" I downloaded Eudora and we had exactly the same issue "SMTP server 550 not localhost not a gateway" (we were trying to email a hotmail account)

What is strange that it does work on my email address. It emails my email address fine but no-one else. When I go to Connection Doctor in mail it states their is no problem with either incoming or outgoing but when we try and send mail, we get a popup saying "SMTP server does not require authentication" and we have the choice of a drop down and selecting a different server. I have tried no authentication and spoken to my hosting company but they say it is needed. One issue is this list seems to self populate itself and I have deleted all accounts and servers, added one email account and that drop down has 3 choices. I have deleted all these and set it up fine so there is only the one choice but with still no joy.

Obviously I have checked all the usernames, passwords etc as I have it working on my own mac so its not that.

Its as if its not clearing out the old settings when we delete all accounts servers, some of the settings seem to remain and it wont accept the new settings even when we type them in.

If you could shed any light on this I would be most grateful.

Paul Derby

There are a number of situations that might keep SMTP connections from working. You mention that you both have the same ISP, are you saying that you both have the same ISP at the local end as well as the mail server location? From what you describe, I suspect that you have the same ISP for mail services, but different ISPs where your computers are located. So you might be able to send mail from your office, but your client can't send mail from their office. If this is so, then the ISP your client has at the local end may be blocking the SMTP traffic. One way that MIGHT work to get around this is to download MAILSERVE from Cutedge and do your own SMTP sending directly from your sending machine. This nifty little helper utility enables POSTFIX on your machine and allows direct sending of email rather than having to deal with ISP SMPT issues. There also is an easy way to view the log when you send email so you get a better clue when things don't work.

Hope that gets you started in the right direction.


Staff member
You mention that the ISP says authentication _is_ needed for SMTP. So let's see: Is the information you enter for authentication of the SMTP-server correct? I'm asking this because if your client uses a private E-Mail address (and not one issued by the provider) and you're trying to authenticate with that, the SMTP server might simply not *know* about this user and thus rejects the user/password combination.

The workaround of installing your own SMTP server (postfix) seems like overbombing to me. (Also, having SMTP on the client's computer makes it look like all mail delivers fine, even with no network connection at all, because it takes your message and _then_ tries to deliver it later.)

I'd let the ISP walk you through setting up the E-Mail account. Pay attention to the SMTP-authentication bit mostly. If they have info on how to set it up available online, maybe you could link to it? Even if it's information for Windows, that'd be okay, because we'll then figure out what you have to do in exactly.