Solved E-mail sending problem

[reco326]

Hi there, today I'm having problem to organize a webmeeting because my colleauges do not receive the invitation email. All of them are set up as extensions and use a business email [email protected].
If I try to send an invitation to my personal email [email protected] it's send without any kind of problem.
The email server setup is the "3CX SMTP Server".
What I can do to solve the problem?
thanks in advance

 

[cobaltit]

Did it ever work? Did you make any email changes recently? About the only issue with 3CX SMTP is that if you try to email an invalid email address and it bounces, it will not send email to that address for at least a week. So if you created the extensions before the email addresses existing you're screwed. Only thing to do is to make an alias on your mail server and change the 3CX extension to use that. But if that's not the case then I would check the logs on your mail server. Where is your email hosted?

 

[reco326]

Hi Cobaltilt, thanks for your reply. It was working until Friday. No change made in the mail server which is hosted on Aruba (italian provider). I can't check, for this reason, any logs. I can try to contact them but I don't know what I have to ask. I mean, in what the mail server is involved? When I send an email from my account to another inside my domain (or outside anyway) there is no problem. The only thing that I can do is to open a support case to check if there is problem or some black list for [email protected]. Is this enough?
thank again

 

[cobaltit]

Basically just tell them what you told us. That you are attempting to send email to your account and aren't receiving it and can they look to see what it might be. What you can do is send a welcome email to your gmail account and then another to your company email. Show them the copy that went to gmail and say you sent one right after to your company email and never received it and if they can check the logs to see any delivery attempts.

 

[reco326]

Hi Cobaltit, I have tried to contact the technical support but they said that for them eveything is ok. They can't give me the logs due to preserve client's privacy. So at the moment I don't know what I can try to do.....do you have any suggestion? thank you

 

[reco326]

Hi again, they have called me and they said that on 3CX SMTP Server are missing the record MX and A associated with reco326.com domain! Therefore, What I can do to solve this problem?

 

[reco326]

is all day that I'm getting crazy....finally I found out that in a log there is an access denied 5.7.0.....
I've read that this happen when the IP which is used to send email is different than the FQDN IP. I have installed the system on AWS EC2 instance and I did all the checks that I was able to do.....
Can someone help me to find out what is going on?
thanks again

2020/03/25 17:19:13.567|654|0003|Excpt|MailKit.Security.AuthenticationException: 535: 5.7.0 Denied ---> MailKit.Net.Smtp.SmtpCommandException: 5.7.0 Denied
--- End of inner exception stack trace ---
at MailKit.Net.Smtp.SmtpClient.AuthenticateAsync(Encoding encoding, ICredentials credentials, Boolean doAsync, CancellationToken cancellationToken)
at MailKit.Net.Smtp.SmtpClient.Authenticate(Encoding encoding, ICredentials credentials, CancellationToken cancellationToken)
at MailKit.MailService.Authenticate(Encoding encoding, String userName, String password, CancellationToken cancellationToken)
at TcxMail.MailTemplateSender.Send(XDocument template, Func`2 getParameter, String mailTo, IEnumerable`1 attachments, Func`2 needEncode)
at _3cxSystemService.EventNotifier.ErrorEventNotifier.SendPbxErrorCodeEmail(Int32 evtId, Int32 type, DateTime dt, String source, String message, String[] prms)
2020/03/25 17:19:14.645|654|0003|Excpt|MailKit.Security.AuthenticationException: 535: 5.7.0 Denied ---> MailKit.Net.Smtp.SmtpCommandException: 5.7.0 Denied
--- End of inner exception stack trace ---
at MailKit.Net.Smtp.SmtpClient.AuthenticateAsync(Encoding encoding, ICredentials credentials, Boolean doAsync, CancellationToken cancellationToken)
at MailKit.Net.Smtp.SmtpClient.Authenticate(Encoding encoding, ICredentials credentials, CancellationToken cancellationToken)
at MailKit.MailService.Authenticate(Encoding encoding, String userName, String password, CancellationToken cancellationToken)
at TcxMail.MailTemplateSender.Send(XDocument template, Func`2 getParameter, String mailTo, IEnumerable`1 attachments, Func`2 needEncode)
at _3cxSystemService.EventNotifier.ErrorEventNotifier.SendPbxErrorCodeEmail(Int32 evtId, Int32 type, DateTime dt, String source, String message, String[] prms)
------------|Inf(00)| Date: 3/25/20 5:21:18 PM

 

[cobaltit]

So if the SMTP traffic from the 3CX instance comes out from a different IP than what 3CX shows in the dashboard it won't like it. Try setting your network from static to STUN, reboot, wait a few minutes and then set it back to static and reboot.

 

[florink]

Does your server have a static IP? On the 3CX dashboard do you get an IP MISMATCH error on the top right?

 

[reco326]

Goodmornig, I don't know how it was but everything at the moment is working. Yesterday I had problem to connect at the administration panel and I did a reboot for the umpteenth time.....I would like to understand but I can ensure that there was not mismatch and any alert for IP address. My IP is static and checking the IP that was use to go externally it was the same of FQDN IP and domain...anyway thanks a million to all.
keep in touch if the problem will appear again