These examples demonstrate the mailman object’s VerifyRecipients method:
ASP: Verify Email Addresses with VerifyRecipients
SQL Server: Verify Email Addresses with VerifyRecipients
C#: Verify Email Addresses with VerifyRecipients
C++: Verify Email Addresses with VerifyRecipients
Delphi: Verify Email Addresses with VerifyRecipients
Visual FoxPro: Verify Email Addresses with VerifyRecipients
Java: Verify Email Addresses with VerifyRecipients
Perl: Verify Email Addresses with VerifyRecipients
Python: Verify Email Addresses with VerifyRecipients
Ruby: Verify Email Addresses with VerifyRecipients
VB.NET: Verify Email Addresses with VerifyRecipients
Visual Basic: Verify Email Addresses with VerifyRecipients
VBScript: Verify Email Addresses with VerifyRecipients
Important: SMTP servers may respond differently when a bad email address is encounted. Here are logs for both mail.chilkatsoft.com and smtp.comcast.net. You can see that the comcast.net server responds with a "550 5.1.1 Not our customer" error, but continues to accept additional recipients. However, the chilkatsoft.com mail server aborts after the 1st bad email address is encountered, and this causes the VerifyRecipients method to fail.
Also, a mail server can only verify the recipients local to it’s domain. For example, comcast.net can only verify comcast.net email addresses, and chilkatsoft.com can only verify chilkatsoft.com email addresses. Any non-local email addresses are assumed to be valid. SMTP servers relay these to the destination mail servers, and if the email is invalid at that point, a bounce notification (DSN) may be generated…
220 OMTA12.emeryville.ca.mail.comcast.net comcast ESMTP server ready
250-OMTA12.emeryville.ca.mail.comcast.net hello [***.***.***.***], pleased to meet you
250-HELP
250-AUTH LOGIN PLAIN CRAM-MD5
250-SIZE 15728640
250-ENHANCEDSTATUSCODES
250-8BITMIME
250-STARTTLS
250 OK
MAIL FROM:<support@chilkatsoft.com>
250 2.1.0 <support@chilkatsoft.com> sender ok
RCPT TO:<a_real_person@comcast.net>
250 2.1.5 <a_real_person@comcast.net> recipient ok
RCPT TO:<doesNotExist7434@comcast.net>
<strong>550 5.1.1 Not our Customer</strong>
RCPT TO:<admin@chilkatsoft.com>
250 2.1.5 <admin@chilkatsoft.com> recipient ok
RCPT TO:<doesNotExist@chilkatsoft.com>
250 2.1.5 <doesnotexist@chilkatsoft.com> recipient ok
RCPT TO:<DoesNotExist7213@gmail.com>
250 2.1.5 <doesnotexist7213@gmail.com> recipient ok
RCPT TO:<chilkat.support@gmail.com>
250 2.1.5 <chilkat.support@gmail.com> recipient ok
Here is the chilkatsoft.com LastErrorText. You can see that this mail server aborts after the 1st invalid email address:
ChilkatLog:
VerifyRecipients:
DllDate: Nov 14 2007
Username: Chilkat
Component: Ruby
SMTP_Connect:
Connecting to SMTP server mail.chilkatsoft.com:25
smtp_host: mail.chilkatsoft.com
smtp_port: 25
smtp_user: admin@chilkatsoft.com
InitialResponse: 220 xmail02.myhosting.com ESMTP 648143d3667b3045487bb901
cdbbf649
sendingHello: EHLO CK2007
helloResponse: 250-xmail02.myhosting.com
250-PIPELINING
250-SIZE 100000000
250-DATAZ
250-AUTH LOGIN PLAIN
250 8BITMIME
login_method: LOGIN
CONNECTED to ESMTP server mail.chilkatsoft.com:25
recipients:
to: a_real_person@comcast.net
to: doesNotExist7434@comcast.net
to: admin@chilkatsoft.com
<strong> 554 Sorry, no mailbox here by that name. (#5.1.1)
Failed when sending RCPT TO:<doesNotExist@chilkatsoft.com>
bad_address: doesNotExist@chilkatsoft.com
Connection closed by server.</strong>
Socket is no longer readable
Failed to get SMTP command response…
This blog post provides more information about validating email addresses:
Validating an Email Address
