DF_MailStuff

DF_MailStuff is a freeware .NET component useful in any circumstances you need to validate/check mail address input by the user.

Do you collect Internet mail addresses or accept addresses typed into a web form? If so, you already know the problems bad mail addresses can cause. Effective validation requires an in-depth knowledge and the correct implementation of the Internet standards relating to mail addresses and delivery protocols. When you need robust validation with ease of use, our library delivers advanced capabilities through its object oriented interface. With just 2 lines of code, you can check the syntax, domain, and user name of any mail address.

The library is ready for immediate use, has no external dependencies, and can be incorporated in to your new or existing scripts in minutes. Using the library you can:

Specify the validation level to perform on any query
Perform full syntax and several rules checking of any address based on current Internet standards.
Quickly identify invalid top level domains, private, and unreachable domains.
Determine if the specified mail address is from a well known free email domain.
Issue real time DNS queries to ensure the domain exists and retrieve the MX records pointing to its mail servers.
Issue real time SMTP requests to contact the domain's mail servers and see if they will accept mail to the address.
Issue real time WhoIs requests
Uses complex heuristic algorithms for catching invalid email addresses.

Bonus: extract mails addresses inside a test you pass to the library.
DF_MailStuff returns detailed error codes.
A full log is available as array or text file.