Cannot send mail - have I corrupted Mail?

Does this happen with ALL emails that you try to send, or just one or more specific email addresses? And you can send emails to these recipients with no problem from your other email account? Is this "main" pop account that is giving you these problems provided by your ISP or no?

In many cases, ISPs will block email traffic sent by you to port 25 of an smtp server that they do not own. If this mail account is NOT provided by your ISP, I would try changing the smtp port number to 587 (as you have already tried) in addition to selecting username/password authentication and SSL (you didn't say whether you had tried these last two things or not).

Who is your email provider of this "main" account? I would be amazed that they didn't provide a web link to an account setup document online. If they are not your ISP, I would seriously consider dumping that provider if you are paying money for the service and you are neither getting the service nor are they being responsive to the needs of a paying customer.

What bothers me here about your smtp settings is that ... well ... let me digress: ISPs that don't require authentication for sending mail can get away with that because one of their authentication criteria that they can use is to filter on the IP address of the sender. If an email is not destined for an address in their domain, then it is considered a relay attempt off of their server, and the only way they could differentiate it from a spammer is to see if it is coming from an authorized user. That either means username/password authentication, some sort of public key authentication (I personally know of no providers that do that, although I am sure that they exist), or validating the IP address of the sender as "one of theirs." The latter method is how an email provider, who is also the ISP, could authenticate valid users that can relay email through their server.

But you say that this email provider is a third-party provider not affiliated with the ISP. That means that he likely is not on the ISP's subnet. If he were to accept email from anyone not on his subnet to be relayed to any address not on his subnet without requiring some sort of authentication, then any spammer in the world could use him. So that's why I don't understand why you can't or aren't using some sort of authentication mechanism on smtp. And if you were... using it without SSL? Then your username and password is sent in the clear and any nefarious internet evildoer parked upstream from you could sniff your mail account login. Plus, you are using SSL with username/password authentication for your POP services. I find it unusual that a third-party email provider that requires SSL to receive email would not enforce the same provisions on sending.

If this is indeed the case, and spammers have latched onto this smtp server, that could explain why your email doesn't get through to anyone, too; anything from that domain is probably on the worldwide "naughty smtp server list" and has been blackballed by reputable email providers.

You haven't divulged who is the email provider, so I wasn't able to search the email provider's website, if they have one, for directions posted online to properly configure your email account. I could be wrong, but I just don't think that port 25 in the clear with no authentication would be correct, any more than I think that that is a very wise choice. Is that what their technical support customer service people told you how to set up to send mail?

It would certainly seem that if this is how it used to work for seven years, and now all of a sudden it no longer does on two different computers, then something on their end has changed. And if they're not working with you to resolve the problem, it's a good thing that it is a free email account. At least you're getting what you pay for.

You can always start sending from the second email account, and configure Mail's preferences to always send from that account regardless of which account you are presently viewing. Since the secondary ISP mail account is a paid account, when viewing the "main" account, and when sending from there, I'm thinking that an outbound email from you would probably take on the identity (i.e., the "From:" address) of the account being viewed, even though you were using the ISP's smtp server and not the smtp server of the "main" account.

Also, to answer your one question, to the best of my knowledge, nothing in the Advanced tab influences smtp in any way. To the best of my knowledge, only where you edit server settings, or add to/edit the smtp server list, influences smtp behavior.

Well, there may be two things going on. The first, if you are trying to send mail from your computer and have it delivered to port 25 of virgin.net, your ISP could be blocking it because many ISPs will only permit traffic destined to port 25 of an smtp server that they own and not to a third party. If you want to use somebody else's smtp server then that's why they have username/password authentication on port 587 or 465 with SSL.

The second, I am outright confused why your webmail is being blocked by virgin.net, unless they have blacklisted you as a sender. If the error message you quoted was really in response to a message sent via web browser, and if there is actually telephone tech support, and if the entire message was returned with any/all attachments, I'd see if there was a way to get it to them and have them explain what is causing that block. If it were from a forwarded mail message that had an attachment that came from a Windows user, I could more likely understand the tagging of this thing as having a virus.

I paid their website a visit, looking for account configuration information. Personally, I didn't find their account configuration and support pages to be worth the electrons that selflessly gave their lives in order to display virgin.net's "help" webpages on my computer's screen. They tell you the server name, there is no mention of port number, SSL, whether you need username/password to send and the directions for Mac are written for Outlook Express ... helloooo? How long has that been deprecated by M$??? So I don't even know whether OE would allow you to change port numbers or set up authentication and if not and that is all that virgin.net supports, maybe you can't use anything other than port 25 non-authenticated with virgin.net. That leads back to the issue of your ISP, then, possibly blocking port 25 traffic that is not destined to be delivered to their smtp server. Someone that is more familiar with virgin.net than I am is going to have to weigh in here to help you further in that regard. I can't find enough information about configuring virgin.net for smtp to tell you anything further that would be meaningful.

In the interim, hopefully, your ISP will let you send email through them, even though the apparent "From:" address is the virgin.net address and not the "your_isp.net" address. Did you find where to set that up in Mail's preferences? I would be curious as to whether that works for you or not. One of my mail account's is a university account. When off campus, the university makes you use your ISP's smtp server; they won't let you use theirs. When that mail account is the selected (active) account in Mail.app, a message sent from there, even though it is relayed through my ISP's server, has the university account's email address as the "From:" address. Not everybody lets you do that, though. Hopefully your ISP will.

Well, I have just found this webpage for configuring Apple Mail.app. See items #9 in both the 10.2 and 10.3 directions. As I review these instructions, it would seem to me that these directions would only apply to their dial-up or their broadband on their network since they are talking non-authenicated smtp on port 25. But they are not your ISP, correct? So I don't know how they let people send email when those folks are on a foreign network. As I said in my previous post, someone who has a working virgin.net account needs to weigh in here. And then, why your emails sent via webmail are tagged as being spam- and virus-laden, I have no clue.

BTW - in your 1st 2 posts, the message "Cannot send message using server xxx.xxxxx.net", was that smtp.virgin.net or mail.virgin.net or whatever.virgin.net, or was it your ISP's smtp server name?

That's unfortunate that my work-around suggestion didn't work for you. Here is what I have to do with my university account, doublecheck and see if it sounds the same as what you tried to implement with your virgin.net account:

My university account, in Mail Prefs Accounts Info, has "school" as the description and "me@university.edu" as email address. Incoming server is "mail.university.edu", with appropriate user name and password to retrieve mail from there. In Advanced panel, I use port 993 with SSL checked (coz' it's a imap acc't w/SSL - pop w/SSL would use 995 - pop and imap w/o SSL would be 110 and 143 respectively).

Back over in Acc't Info, in outgoing mail server, I use "smtp.isp.com" as the server for the "school" account coz', like I said, the university blocks all smtp traffic that is not destined for ultimate delivery to an account on their mail server, that is arriving from a non-university IP address. The university's instructions are to use your email provider's smtp server for outgoing. It just so happens that my ISP doesn't mind what I use as an originating email address and they let me relay email through their server because they authenticated me by my IP address, which they assigned to me. My ISP tells us to use port 25 non-authenticated w/o SSL for the smtp server because they have already authenticated me based on my IP address so no username/password required to access the outbound mail server.

Then over in Mail Prefs Composing, there is a pulldown menu "Send new mail from:" I told you earlier to choose your ISP mail account - my bad - you should be able to use "account last viewed" since you specified the ISP's smtp server as the outgoing mail server for the virgin.net account - that is how I am set up using my ISP's smtp server for my school account.

Now this assumes that your ISP doesn't check to make sure that your "From:" domain name matches their domain name. I know AOL does that check on their free email accounts and they block mismatches, but my ISP does not enforce that restriction on my paid email account. They know who I am from my IP address that they have assigned to me, so if they were to ever get abuse reports, they'd be able to find me.

So doublecheck that you have set up your virgin.net account similarly to how I set up my "school" account, specifying your ISP's smtp mail server as the outgoing mail server, and try going back to "Account of last viewed mailbox", and see whether your ISP will let you send email as apparently being from your virgin.net address. I apologize I don't seem to be much help getting this to work for you.

Based on this latest error message, then just for laughs, on your newly modified version of your virgin.net account, that now specifies "smtp.isp.net" as the outgoing mail server, try changing to username/password authentication with SSL checkbox checked using either port 25, 587, or 465, and see what happens. It wants to be authenticated, so let's try to authenticate. If no workie, try again except with the SSL checkbox unchecked.

I think that the other server (virgin.net) doesn't want unauthenticated traffic that's not being originated on their network (they are not your ISP so you are not on their network). You would have to ask them how to configure your email client for sending email through their smtp server when you are not on their network.

Darn! Sorry I wasn't able to help you resolve your problem. I'm sure it's got to be frustrating -- I guess I am darned lucky that I have dodged all the bullets on all the Mail, iChat, and networking issues that I read about and/or try to help people resolve in these forums...so far.

There are some people in this forum that are way smarter than me; now that I have run out of ammo, perhaps they will jump in and help now.

...and that would be a POP account on virgin.net and not using virgin.net as their ISP.

Good luck to you!