West Wind Internet and Client Tools
SMTP Email Sends Always Fail
Gravatar is a globally recognized avatar based on your email address. SMTP Email Sends Always Fail
  PAUL WEISBERG
  All
  Dec 23, 2021 @ 09:02am

I am having a problem with SMTP emails that I have never had in the past in many versions of my product. Rick - I have a patched install from you for the problems I was having with cancelling SFTP downloads. Maybe this is related?

I have a development environment inside a virtual machine. Inside the virtual machine, built .exe file, smtp email works fine, no issues at all. If the same .exe is distributed and installed on a customer's machine, smtp emails never work but an error is returned instead: "5.7.1 ...Relaying denied: You must check for new mail before sending mail"

Both systems are Windows 10, both systems are using the exact same email parameters/setup as a test. But outside the development Virtual Machine it never works.

Gravatar is a globally recognized avatar based on your email address. re: SMTP Email Sends Always Fail
  Rick Strahl
  PAUL WEISBERG
  Dec 23, 2021 @ 12:20pm

That's a message from your email server - looks like you have to log in to the POP server first before you're allowed to send SMTP messages. Unrelated to the client - it's a server configuration issue. Either the policy changed on the server or you were already logged in before sending email at other times.

+++ Rick ---

Gravatar is a globally recognized avatar based on your email address. re: SMTP Email Sends Always Fail
  PAUL WEISBERG
  Rick Strahl
  Dec 23, 2021 @ 12:40pm

Hi Rick, it does seem to be a message from the server but the same program with same email parameters within the development environment throws no errors. And this application and this email server have worked for years. I did upgrade my wwClientTools recently and I must have something wrong in the distro. But I don't know what it could be. I have a strong feeling that launching outlook before this messes it up. Because in the VM I have no email client. That's the only diff I can think of.

Gravatar is a globally recognized avatar based on your email address. re: SMTP Email Sends Always Fail
  Rick Strahl
  PAUL WEISBERG
  Dec 23, 2021 @ 02:10pm

It's most definitely a message from the server and it requires you to connect to the POP/LDAP server first before you're allowed to send messages via SMTP. This used to be a fairly standard thing to do with older mail servers, but very uncommon with most mail services.

You need to find out what the protocol is. If it's POP3 that lets you log in you can perhaps set it up with wwPop3. It's not standard SMTP functionality...

+++ Rick ---

Gravatar is a globally recognized avatar based on your email address. re: SMTP Email Sends Always Fail
  PAUL WEISBERG
  Rick Strahl
  Dec 23, 2021 @ 03:24pm

OK thanks Rick, agreed.

I found another outgoing server name and different port for my ISP that DOES work but I am questioning the security on that one. Needs more research.

What I just cannot figure out is why it works fine from inside a virtual machine but not outside the VM. It's the same PC, the same program, the same email parameters. I'm still scratching my head on this one.

Gravatar is a globally recognized avatar based on your email address. re: SMTP Email Sends Always Fail
  PAUL WEISBERG
  PAUL WEISBERG
  Dec 23, 2021 @ 03:57pm

Hmm, I got it working. All I did was log in to the email server via a browser interface. After doing that there are no further failures and smtp mail sends are working. The only thing I can imagine is that logging in reset something in the account or possibly just "read the email" like it was complaining about, or possibly there was some sort of timeout on the server that had to occur - I have no idea. Even after logging out of the browser interface it's still working fine. But I will never be able to explain why it always worked fine inside a VM but not outside. Don't think I'll lose any sleep on that one. 😃

I guess one more test would be to reboot the PC and see if the problem returns....

Gravatar is a globally recognized avatar based on your email address. re: SMTP Email Sends Always Fail
  Rick Strahl
  PAUL WEISBERG
  Dec 23, 2021 @ 08:54pm

That's possible but more likely it detected the recent login and that then allows the sending.

If that's the case that's not a solution though because you would always have to do this.

Frankly the better solution is to use an email service (like Mailgun, SendGrid, Twilio etc.) rather than an ISP/provider. These days any non-service provider email service that is geared toward end user email accounts tend to have problems with email quotas and reliability due to the security issues dealing with email sending as mail servers are constantly under attack for vulnerabilities.

+++ Rick ---

© 1996-2022