Emails Fired from Outlook are not Delivered to Recipient
Posted on 2016-09-13
We are using 3rd party Windows Hosting server from dailyrazor.com and using their SMTP and pop credentials for Emails as well. Lets assume our domain is www.abc.com
Our company email accounts are configured on outlook and we are using pop and smtp to connect to their server and both of these addresses are mail.abc.com and obviously uses 110 port for pop and 25/8025 for smtp.
Till now for 6 years, this was running fine but suddenly day before yesterday, emails from outlook were sent successfully and were transferred to sent folder but it was not received by the recipient. I investigated further and sent an email from firstname.lastname@example.org to email@example.com and both of these emails are configured in my outlook itself. After sending the email, I went to webmail of firstname.lastname@example.org to see whether email was there and there is some problem in receiving but actually email was not there itself.
So email was sent from outlook but vanished in between or went to different folder in the email server rather than inbox folder of email@example.com
There are several other tests which I did:
a)when I sent an email from webmail of firstname.lastname@example.org to email@example.com then email was delivered which made me think that webmail might be using different smtp port than 25/8025. But as per hosting provider they said it is same- 25. Also same emails are configured on my
blackberry mobile and if I send from there then also it gets received by the recipient. So the issue is only sending emails from outlook which infact shows its sent though its not received by recipient (infact is not showing in server inbox on webmail as well).
b) When I sent an email from gmail.com or any other domain which is not hosted with dailyrazor then email gets delivered to the recipient which cleared that problem is with smtp of this computer
c) I though we are in india so my ISP (Airtel) is blocked but not sure then email should not have gone into sent folder. Also I ran telnet command with port 25 and 8025 , it returned successful. But still on safer side, I tried another ISP (Vodafone) and it failed for that as well which means ISP is not blocking. Correct me if I am wrong.
Please help me if there is some sudden problem with Outlook or if the hosting provider has to do something. They are actually not competent to find the cause and saying everything is working.
Does all Indian ip addresses are blocked for this domain by Hosting Provider’s ISP? Is that a possibility? But in that case telnet should not have returned successful. Correct me.