Email validation service is a .NET based web service.

Click here to view WSDL.

Click here to check the service. Use the key TEST-TEST-TEST-TEST. it will allow up to 5 address verifications from the single IP address a day.

Detailed description of methods follows:

VerifyAddress(string email, string key)

returns a string, either Valid, Invalid, or Unknown.

Valid means, that service contacted an exchanger of destination domain, and discovered, that the exchanger is willing to accept mail for the email address (issued 200 series SMTP reply).

Invalid means, that the service contacted an exchanger of destination domain, and discovered, that the exchanger refused to accept mail for that email address (issued 400, or 500 series SMTP reply).  Invalid is also returned when destination domain name does not exist.

Unknown indicates that the service either was unable to contact the exchanger due to an error (including timeout), or exchanger reply was not clear (e.g. 400 series reply, indicating a temporary failure).

If you need to know what does exactly happen, use VerifyAddressEx method (see below).

VerifyAddressWithTimeOut(string email, int timeOut, string key)

Works as VerifyAddress, but allows to specify the timeout value in seconds.  In case of timeout, Unknown is returned.  In case of VerifyAddress, timeout is 10 seconds.

VerifyAddressEx(string address, string timeOut, string key)

Returns a string value, containing CRLF separated data.  First line contains the similar result as for above methods (Valid, Invalid, Unknown), follwed by the detailed log.  This method will allow to follow the validation process.

Following methods are available only to registered users.  They will return correct result only when key matches an assiciated email.  This association happens when user signs up for the service.

KeyExpires(string key, string email)

Returns date, when the key expires.

RemainingAttempts(string key, string email)

Returns the number of remaining key usage attempts until midnight GMT.

Download a sample of using the service (C#, .NET 2.0, 375 KB).