Autodiscover service couldn't be located
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Hi, I have a simple test application that allows me to send an email message through an Office 365 account. When I run this application from say my home PC it works fine, but when I run it from any machine on my company's network, it doesn't work. The application allows for two different methods of sending a message, a simple smtp server address and a webservice. When running the application I get a different error for each method: - smtp server:
Quote:
No connection could be made because the target machine actively refused it
- webservice:
Quote:
Autodiscover service couldn't be located
Our system administrator tells me our firewall is not blocking the port, and has not been able to suggest anything else. We only recently switched from third party Exchange 2010 to Office 365 and our on-premise AD is synced to it. MS Outlook works fine. Our office scanner also cannot send scans to email anymore, which it could through Exchange 2010's smtp server. I am at a loss, and any help with this issue will be much appreciated. Regards, Johan
My advice is free, and you may get what you paid for.
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Hi, I have a simple test application that allows me to send an email message through an Office 365 account. When I run this application from say my home PC it works fine, but when I run it from any machine on my company's network, it doesn't work. The application allows for two different methods of sending a message, a simple smtp server address and a webservice. When running the application I get a different error for each method: - smtp server:
Quote:
No connection could be made because the target machine actively refused it
- webservice:
Quote:
Autodiscover service couldn't be located
Our system administrator tells me our firewall is not blocking the port, and has not been able to suggest anything else. We only recently switched from third party Exchange 2010 to Office 365 and our on-premise AD is synced to it. MS Outlook works fine. Our office scanner also cannot send scans to email anymore, which it could through Exchange 2010's smtp server. I am at a loss, and any help with this issue will be much appreciated. Regards, Johan
My advice is free, and you may get what you paid for.
Quote:
No connection could be made because the target machine actively refused it
Try to get the original error message send by the "target" (an SMTP error message or an ICMP message from a router/firewall at the target). It should be helpful.
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Quote:
No connection could be made because the target machine actively refused it
Try to get the original error message send by the "target" (an SMTP error message or an ICMP message from a router/firewall at the target). It should be helpful.
Hi, Thanks for your reply. I set the application to specifically show smtp errors, but the error remains the same:
Quote:
System.Net.Mail.SmtpException: Failure sending mail. ---> System.Net.WebException: Unable to connect to the remote server ---> System.Net.Sockets.SocketException: No connection could be made because the target machine actively refused it 40.101.88.18:587
Quote:
(an SMTP error message or an ICMP message from a router/firewall at the target)
The application works fine when I run it on any machine that is not on our network. Wouldn't that suggest that the error is caused by our own network, but somehow is not interpreted as a remote error? I can ping 40.101.88.18 normally. Regards, Johan
My advice is free, and you may get what you paid for.
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Hi, Thanks for your reply. I set the application to specifically show smtp errors, but the error remains the same:
Quote:
System.Net.Mail.SmtpException: Failure sending mail. ---> System.Net.WebException: Unable to connect to the remote server ---> System.Net.Sockets.SocketException: No connection could be made because the target machine actively refused it 40.101.88.18:587
Quote:
(an SMTP error message or an ICMP message from a router/firewall at the target)
The application works fine when I run it on any machine that is not on our network. Wouldn't that suggest that the error is caused by our own network, but somehow is not interpreted as a remote error? I can ping 40.101.88.18 normally. Regards, Johan
My advice is free, and you may get what you paid for.
Quote:
No connection could be made because the target machine actively refused it
That means that there is no service listening on the specified port or a firewall is blocking the request (at the target side). When you can connect from other systems (did you use the same server name and port number 587 there?), it must be a firewall that is blocking requests by the source IP (IP is black listed or not white listed). 40.101.88.18 belongs to Microsoft. Which SMTP server name have you specified?
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Quote:
No connection could be made because the target machine actively refused it
That means that there is no service listening on the specified port or a firewall is blocking the request (at the target side). When you can connect from other systems (did you use the same server name and port number 587 there?), it must be a firewall that is blocking requests by the source IP (IP is black listed or not white listed). 40.101.88.18 belongs to Microsoft. Which SMTP server name have you specified?
My first guess was also that the problem is in our firewall, but I only asked our admin about a port being blocked. I will have to ask again about a possible black/white listing. Thanks for that suggestion. As for the SMTP server, per MickeySoft's instructions I use smtp.office365.com and port 587 or 25. I suppose that address has its own autodiscover protocol. nslookup gives me the specific smtp server name outlook-emeaeast3.office365.com and 9 different IP addresses. What I have been wondering about is, how MS Outlook contacts exchange online. Why is it not having any problem connecting?
My advice is free, and you may get what you paid for.
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My first guess was also that the problem is in our firewall, but I only asked our admin about a port being blocked. I will have to ask again about a possible black/white listing. Thanks for that suggestion. As for the SMTP server, per MickeySoft's instructions I use smtp.office365.com and port 587 or 25. I suppose that address has its own autodiscover protocol. nslookup gives me the specific smtp server name outlook-emeaeast3.office365.com and 9 different IP addresses. What I have been wondering about is, how MS Outlook contacts exchange online. Why is it not having any problem connecting?
My advice is free, and you may get what you paid for.
The error message indicates that a target / remote side refuses the connection. This is usually a system behind the first router (the first router should send a different message when he blocks outgoing attempts). I don't think that MS is blocking accesses from your company. Because it works on other sites, it is most probably sourced somewhere in your company network or your companies internet provider. Many companies block outgoing SMTP except for white listed source IPs (e.g. only a local forwarding SMTP server is allowed to talk SMTP to the net). The network admin in your company is the responsible person to contact. Even if he tells you that there are no filter rules, he might help better because he should know the toplogy of the company network.
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My first guess was also that the problem is in our firewall, but I only asked our admin about a port being blocked. I will have to ask again about a possible black/white listing. Thanks for that suggestion. As for the SMTP server, per MickeySoft's instructions I use smtp.office365.com and port 587 or 25. I suppose that address has its own autodiscover protocol. nslookup gives me the specific smtp server name outlook-emeaeast3.office365.com and 9 different IP addresses. What I have been wondering about is, how MS Outlook contacts exchange online. Why is it not having any problem connecting?
My advice is free, and you may get what you paid for.
So you have the correct SMTP Server - smtp.office365.com and correct Port - 587, what Encryption are you using? Microsoft says to use TLS and I bet Outlook is set to use it but have you set it in your code?
Michael Martin Australia "I controlled my laughter and simple said "No,I am very busy,so I can't write any code for you". The moment they heard this all the smiling face turned into a sad looking face and one of them farted. So I had to leave the place as soon as possible." - Mr.Prakash One Fine Saturday. 24/04/2004
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So you have the correct SMTP Server - smtp.office365.com and correct Port - 587, what Encryption are you using? Microsoft says to use TLS and I bet Outlook is set to use it but have you set it in your code?
Michael Martin Australia "I controlled my laughter and simple said "No,I am very busy,so I can't write any code for you". The moment they heard this all the smiling face turned into a sad looking face and one of them farted. So I had to leave the place as soon as possible." - Mr.Prakash One Fine Saturday. 24/04/2004
Hi Michael, Thanks for your response. My apologies, I posted about this problem on another forum as well, and forgot to update this one. As it turns out, our firewall wasn't blocking any ports, it was just not allowing other SMTP traffic than specified, and nothing was specified. Anyway my code was good, including TLS, so the question remains, how come Outlook was not blocked by our firewall, when my code was. Regards, Johan
My advice is free, and you may get what you paid for.