EmailVerify for .NET

EmailVerify for .NET can check if an email address exists without sending email messages; it does so by emulating the behavior of common mail exchangers and employing the SMTP protocol wisely, while respecting the Netiquette rules to avoid the originating IP address being tagged as a potential source of spam. Due to the nature of this check, the validation process may be affected by multiple factors, including network latency and configuration; EmailVerify for .NET keeps track of the eventual errors as well as the possible temporarily failures and report them back for further analysis.

The following code, for example, checks if a given email address exists and, in case of failure, follows different execution paths based on the exact cause of the error, as determined by the component:

            var engine = new VerificationEngine();

            // ...

            var result = engine.Run("bob@example.com",
                VerificationLevel.Mailbox).Result;

            switch (result.Status)
            {
                case VerificationStatus.Success:
                    // The mailbox exists
                    break;

                case VerificationStatus.MailboxDoesNotExist:
                    // The mailbox does not exist
                    break;

                case VerificationStatus.MailboxTemporarilyUnavailable:
                    // The mailbox is temporarily unavailable: we need to validate
                    // it again in a few minutes (greylisting)
                    break;

                case VerificationStatus.MailboxValidationTimeout:
                    // A timeout occured while validating the mailbox; we need
                    // to increase the related settings value
                    break;

                case VerificationStatus.ServerDoesNotSupportInternationalMailboxes:
                    // The local part of the address is in a non-ASCII encoding but
                    // the foreign mail exchanger can't handle this type of addresses
                    break;

                case VerificationStatus.LocalSenderAddressRejected:
                    // The foreign mail exchanger rejected our sender address
                    break;

                case VerificationStatus.SmtpConnectionFailure:
                    // A network failure happened while connecting to the foreign
                    // mail exchanger
                    break;

                // TODO: Add more cases, if needed

                default:
                    // ...
                    break;
            }