I am also encountering a similar error, except mine says, after the registration form is submitted:

E-mail (Required)
Enter an email address. This is necessary in case the password is lost. We respect your privacy, and will not give the address away to any third parties or expose it anywhere.
We were unable to send your password to your email address: (-2, 'Name or service not known')

(The address is a standard hotmail address )

AFAIK, I have the plone e-mail settings pointing at webfaction per the instructions, and the return address for the plone site ( admin@XXXXXXX.org set and matching to an address set up on the webfaction e-mail control panel ( tested - e-mail sent directly to this address passes in and is forwarded to my normal address.

remi wrote:

.... Sometimes the MailHost product seems to get corrupted and the only way to fix it is to recreate a new Zope/Plone instance (if you're sure that you use the right settings).

Regards,

Remi.

If this indeed the case, what is the damage control measures, and can this happen at any time, or just when the Zope/Plone instance is created ( in which case I suppose an e-mail test should be one of the first things checked. If the initial set-up is corrupted, if there is already content added and edits to the plone site, is there a way to migrate the previous installation to the new one? Is this error peculiar to certain Zope/Plone versions and/or combinations?

Michael

Thanks to Mike, we now have a solution to this problem that doesn't involve re-creating a new Zope/Plone instance:

indymike wrote:

Here is how to fix the problem
without having to create new instances:

1. Go to the plone site that is having problems in the ZMI.
2. Delete the existing MailHost.
3. Add a new SecureMailHost. Name it MailHost and title it Plone Mail
Host. Enter your SMTP info.
4. Test.

The issue is that the MailHost object in the database is sometimes
adding a strange character to the sender's email address in the mail
host. I'm not sure if this has been patched for the next version of
plone or not. Deleting the DB object and creating a new one gets rid of
the corruption.

I found the way to add SecureMail (through the Add dropdown in the zmi). So I dropped the mail server and added the secure mail server. But now, when I go to my plone app, and click on site setup, I get a warning that says:
Warning
    You have not configured a mail host or a site 'From' address, various features including contact forms, email notification and password reset will not work. Go to the Mail control panel to fix this.
I click on the Mail icon, and it still remembers all my previous settings from the old mail server setup. But clicking save does not make the warning go away. I guess the site setup interface isn't talking to the new SecureMail object.
Now what do I do?

harryleblanc wrote:

I found the way to add SecureMail (through the Add dropdown in the zmi). So I dropped the mail server and added the secure mail server. But now, when I go to my plone app, and click on site setup, I get a warning that says:
Warning
    You have not configured a mail host or a site 'From' address, various features including contact forms, email notification and password reset will not work. Go to the Mail control panel to fix this.
I click on the Mail icon, and it still remembers all my previous settings from the old mail server setup. But clicking save does not make the warning go away. I guess the site setup interface isn't talking to the new SecureMail object.
Now what do I do?

Did you give your new SecureMailHost object the ID of "MailHost"?