If your recipient's list is not fresh, chances are that many email addresses are undeliverable. It may be useful to verify addresses before sending.
AY Mail verifies addresses by connecting to the servers and initiating email transfer from the sender to each of the recipients. It then aborts the process as soon as the response about validity of the recipient address is received.
It may not work if one of the following happens:
1. Your ISP block all the SMTP connections (so called port 25 block). This frequently happens with big ISPs who want to prevent their customers from sending spam. If this happens, all your addresses will be classified as temporarily undeliverable (with question mark on the recipient icon) and the status description will be Cannot Connect To the Server. In this case, you need either negotiate with your ISP, or live without address verification. This will also prevent you from using Direct Sending.
2. Your ISPs DNS service does not let you access MX records. If this is the case, AY Mail will connect to wrong servers and address verification will be all wrong. Fortunately, this is a very rare case.
To initiate the address verification process, click on the Recipients tab and select Recipients->Verify Addresses from the main menu. In the dialog that appears, select Verify all addresses .
Address verification usually takes long time. You can verify between 100 and 200 recipients per minute.
After the verification is done, you will see good recipients marked with a green check mark and bad recipients marked with a red cross. Some of the recipients may be marked with a red question mark. This means that the recipient has failed, but there is a chance that the condition is temporary. You can re-try the verification, but this time select Verify only temporarily undeliverable addresses, which will only verify the recipients marked with the question mark.
After address verification, you can disable failed recipients by selecting Recipients->Disable Undeliverables from the main menu. You can then completely delete the disabled recipients from your list by selecting Recipients->Remove Disabled.
Verification does not give you a 100% guarantee either way. AY Mail tries to be conservative and does not mark recipients as undeliverable unless there is a definitive indication of the undeliverability.
Reasons why good recipients may fail:
1. Some ISP may deny your access to their SMTP server because your IP address is blacklisted. See Email Transport Overview for details. AY Mail tries to analyze the verbal response of the server trying to distinguish this situation from a regular failure. AY Mail will do its best to mark such recipients as temporarily undeliverable.
2. Mis-configuration on the SMTP server may make it report a good address as undeliverable. This situation is impossible to detect.
Reasons why bad recipients may be marked as successful:
1. Some servers do not handle mail, but rather pass it to other servers. These servers do not know if the email address exists, so they will accept almost any address. This is a very common situation.
2. Some servers first accept recipients, and only then deal with them. Such servers will report your recipient as good, but then will send you a bounce if the address does not exist.
Reasons why recipients may be temporarily undeliverable:
1. AY Mail cannot get the address of the server to connect to. This may be either temporary DNS failure, or their ISP may be out of business.
2. AY Mail cannot connect to the server. The server may be temporarily down, or it may be no longer working.
3. Connection breaks while talking to the server.
4. Server may report a temporary failure. Server may be busy, out of memory, out of disk space, over the quota, or otherwise unable to accept mail.