SMTP not sending Stackmail

Cannot connect to SMTP to send emails
IMAP works with inbox and Sent

Host is: smtp.stackmail.com
Port: 465
Security policy: Use SSL/TLS on special port (legacy)
Setup was automatic

When doing diagnostics it says IMAP Ok
SMTP “Your credentials were reject”

If I click in Fix, it runs through a lot of connections, then asks for confirmation of user and password. But when given it eventually just asks for these again.

This same setup works with Thunderbird with no problems, and also with Outlook.
Using Windows 11

Nobody seems to be able to help with the problem. It seems to be peculiar to eM Client as I see other people have asked about the same issue and it was never resolved for them.

Why should the settings for this account work in Thunderbird and Microsoft new Outlook, but not in eM Client? I have the same problem on my second computer.

I have installed Mailspring and the account works on that as well, automataically configuring it. yet nothing I can do in eM Client works, though I have 4 other email acconts that work perfectly in it.

For this account all I get is ‘Your credentials were rejected’. But new emails come in, and emails sent from Thuderbird come in. Yet no mssages can be sent from eM Client for this account, and this account only.

Help would be appreciated.

I see a lot of people have looked at this question but nobody has offered any solution. I take it that it is a fault in Em Client and will now give up trying to use it for this account.

I note that other people have had exactly the same problem with SMTP not sending for some accounts with Em Client and nobody found a solution for them.

I am dissapointed as a paid customer I am offered no help at all.

Have you tried port 587, a search of Stackmail brought up the following:

Thank you for your suggestion. Port 465 is the port autosellected. Changing it to 587 makes no difference. Also changing any of the SMTP security options makes no difference. The only one not rejected is SSL/TLS on special port (legacy).

When I run diagnostice it tries many different ports, including these two. It alwasy ends up saying my credentials are rejected. I have checked these are correct and checked the passord is correct.

Thunderbird uses port 993 as default for this account. But that does not work in Em Client. So I am at a loss.

Sorry, Thunderbird uses 456 for SMTP. Port 993 is uded by IMAP.

When doing diagnostics it says IMAP Ok
SMTP “Your credentials were reject”

Under your SMTP tab under the “Authentication” section, have you tried “Use identy credentials” ? rather than typing in your username and password.

As per your IMAP settings works (as passes the diags ok) with your username and password, so setting the SMTP to use your IMAP username and password should then work the same.

Thank you for your suggestion. That is the setting I use and which is set up by default, and which works for IMAP but not for SMTP. It makes no difference if I type in username and password or leave it at ‘Use identy credetials’. There is an alternative ‘Use these credentials’, but that does not work either. They are greyed out but the same.

As you say, the useraneme and password are the same for IMAP and for SMTP but only work for IMAP. Yet these settings work with Thunderbird and Microsoft Outlook.

I have Em Client on two other computers and have the same problem with them. So it is something to do with Em Client itself that causes the problem, it would seem.

I have three other accounts on Em Client, and these all work perfectly.

Ok from reading an old thread where a user @IanW with Stackmail also could not send, it appears the problem was that “the server was using an outdated older CRAM-MD5 authentication protocol from the eM Client logs” so wouldn’t work with newer mail client authentication methods. So was surmised by @AffaMoh that they needed “to force the older plain text authentication” allow to then send mail.

@skybat also advised in that thread the alternative “is to use a different SMTP server”.

There was also another thread where they “also had an older different mail server authentication” and couldn’t send mail due to allways authentication verification problem, but with the below plain text settings from @Gary and @Phil_LP (it then sent mail ok) in V10.

So @jeseph12 and @IanW try putting the following in your IMAP account “Diagnostics” Tab to force the SMTP authentication to use a plain text and see if that will then allow to send mail.

(If you don’t specify the username and password try using the following in the Diag).

image

Or

(If you do specify the username and password in the SMTP tab, try using the following in the Diag).

image

Server smtp.stackmail.com
Port: 465
Security policy: Use SSL/TLS on special port (legacy)

Or

Server smtp.stackmail.com
Port 587
Security policy: Force usage of SSL/TLS

Note: @jeseph12 If trying the above strings still doesn’t allow you to send mail, then click the drop-down arrow on the right of Refresh and click Show Operations. Then click the “Log tab” and look for obvious error messages and paste them in this thread so we can check.

Thank you again for your helpful suggestions. But none of these solve the problem. But I get different messages which I attach. I will send the log you ask for later.


certificate-verify

Ok so you have a certificate problem. Sry I personally don’t know how to fix certificate problems, but others who use certificates on this forum hopefully can assist you with that.

@Gary are you able to help with this ?

This seems to be an irresolveable problem with Em Client. I have no propblem with Outlook, Thunderbird or Mailspring which I have just now tried with this account. They all just automatically configure it and it works. So something is different in Em Client that creates a problem, and which causes it to reject username and password for sending mial. Yet incoming mail works, including sent mail from Thunderbird.

I have no idea what certificates are about since these never crop up on other email clients.

I will await any further help, but am resigned to it never working.

Thank you for all your help.