Suddenly cannot send email through any SMTP server

Since installing the 10.4.9 version, I have been unable to send email. After reading this forum, I tried sending without a signature, didn't work; tried sending via entourage and it did work until I change the format to html and then it failed; then I went back to Apple Mail and tried it in plain text mode and it worked - message sent. If I switch back to rich text, it won't send but with plain text is does send.

But I like rich text. What do I do now other than use plain text? Is this an ISP thing (Qwest) since it pretty much does the same thing in entourage?

I'm having the same problem. Has there been a solution?

Hello cherokeexc90:

Did you try to reinstall Mail 2.1 from the Tiger install disk?

After reading dozens of posts from many people having problems after updating to 10.4.9 [and trying the same remedies], my smtp problems cleared up after I installed a new [uncorrupted?] copy from the install CD.

Try it and see.

I have been trying for the last 8 weeks many of the suggested options above with no success.
This week i churned to a new ISP - lo & behold i can now send emails with attachments, even though i had asked the previous ISP if they were blocking ports which they assured me they weren't?
Seems strange that it only happened after the last update? i too was convinced it was an Apple issue but it appears that it isn't.

I have already done this along with an archive reinstall.

Not yet....I'm working with my ISp to see if there is a problem....

It is not the os . I'm having the same problem on Windows XP

Problem solved, turned out to be the ISP blocking the port to use the smtp server. Took them 4 weeks to find this and I have asked for a refund for service for the time I lost..

Thanks for your input

On 25 April I installed a new security update (sound familiar?) and I couldn't send or receive email. I spent two days trying to get it going--resetting preferences, talking to ISP and so on--believe me I tried everything. Closed the computer down on the night of 25th, and still couldn't send or receive e-mail so I spent another seven hours trying to get it going the following day. This morning I turned it on and everything worked. I think this is a software glitch, and sent Apple an email about it.

Same problem here. Ran the "Security Update 2007-004 (PowerPC)" update this AM. Now I can't send mail, but I can receive. Tried all three port suggestions and nothing worked. When is Apple going to provide a solution to this? It's obviously not user-end error.

There was a block on my smtp server because someone was sending spam from it. I believe one of the emails that was running on windows had the problem. Everything is working fine now.

I've hit similar problems before and the culpret has usually been an offending e-mail I was trying to send or receive. Once that was deleted everything returned to normal (but not before I jumped through some major rebuilding/experimenting hoops). This time the offense was a single e-mail address buried in a large group e-mail I was trying to send. Once I was able to isolate this offensive address and delete it from the e-mail I was trying to send (and deleting all others in the cue) everything returned to normal. I know, it doesn't seem possible that something so simple could be to blame, but the proof is in my once-again-functioning system. No rebuilding the accounts, no changing default ports. Just had to delete one address. I just wish I had figured this out about six or eight hours ago.

My problem is similar but weirder. After over a year with no email problems, I suddenly cannot send an email from any POP application that does NOT have a large attachment. I have spent hours online with my 10 year ISP and Outspring for my Quickmail application.
Absolutes:
I can receive emails from any of my accounts- 1 with my cable ISP (myacc.net) and 3 at other hosts. My ISP uses port 25 no authentication. I can telnet smtp.myacc.net 25 and receive a positive connection message. The Connection Doctor in Mail.app reports everythings perfect. I have the same issue with either Quickmail or Mail.app ( I use quickmail extensively). I have booted the mac in OS 9.2.2 and sent from Quickmail for os 9 with exactly the same results. From Quickmail or Mail.app the email looks like it went through and it goes to my sent mail box just like it should. No email with less than a 300k attachment is actually sent. My ISP doesn't even see a logged event on their server with the emails without big attachments.
I have tried relaying from another SMTP sender using port 587 (my ISP blocks relaying on port 25 but allows relay from port 587)) with exactly the same results. It does not appear OS specific as OS 9 does the same thing. I have a PC running Windows XP plugged into the same hub running Quickmail for Windows and it sends perfectly. This problem started suddenly and without any changes to anything. I have since upgraded from 10.4.6 to 10.4.9 with no change.
I have pulled out all of my hair as have the Quickmail and my ISP support team. There must be a machine based issue but I cannot even imagine what is happening.

powermac g4 dual boot Mac OS X (10.4.9) also can boot os 9.2.2

powermac g4 dual boot Mac OS X (10.4.9) also can boot os 9.2.2

powermac g4 dual boot Mac OS X (10.4.9) also can boot os 9.2.2

I'm totally inexpert and have not yet tried any of the fixes/machinations suggested above, but most of the above experiences parallel mine. 10.4.9 in both places and via the ISP I use at home I cannot send anything out of my .mac account to any other non-.mac account. Same thing at work (my uni, a different ISP).

Everything from either place (different machines, btw) from .mac to a non-.mac address bounces back as undeliverable. (And I'm also in Japan, as are some of the above posters.)

Yikes! Please fix it Apple!

I have been experiencing similar issues. I use Eudora. I think the trouble is related to the OS X updates, too, but my problems eventually involve not being able to get online. I have Airport sent from my husband's PC to my Mac, and everything checks out there.

Here's how it usually goes: Eudora can't send outgoing mail. Then it can't send or receive. Then Safari can't access an address or, today, can't even launch. (Netscape launched, but couldn't get online.)

I have been using Dreamweaver 8 in this same time period, and periodically, at the same time, need to launch Classic OS 9 to work in PhotoShop LE.

The "fix" for me has been to go into Disk Utility and let it fix the Permissions.

This gives me another few days, and then it's time to do the cleanup again.

Anyone with advice about how to fix it -- Apple --- are you there?

Thanks!