The Mail-to-Blogger "Secret" Word Is An Address

Some blog owners use Mail-to-Blogger, for publishing to their blogs, without considering the issues.

Some owners can't get Mail-to-Blogger to work.

I get

Delivery to the following recipient failed permanently:

or

I don't get any error - and the post never shows up in my Posts list.

Other owners have no problems getting theirs to work, and later find posts that they didn't send - and don't appreciate.

Where did all of the spam come from?

Using Mail-to-Blogger seems simple - but maybe should not be treated so. The Mail-to-Blogger email address, at Settings - Mobile and email, is a major part of the challenge, in this case.

The legendary Mail-to-Blogger "secret" word has two complementary - and competing - functions.

• It's an email address.
• It's a password.

You need to keep both requirements in mind - and balance the two, carefully.

The "secret" word is an email address.
Email addresses need to be kept simple. Similar to URLs, remember that any email, that you send, will be passing through various email systems.

• You (and any other authors) will send email, through an outgoing email system.
• Blogger will receive email, through the Google email system.
• Depending upon the location of the system that you (and the other blog authors) use, there could be other email systems.
• Each email system will have its own rules, for accepting and / or translating addresses.

If you want your email to get to Blogger - and to your blog - you will want to keep the 12 to 24 characters simple.

• 26 lower case letters, "a" - "z".
• 10 digits, "0" - "9".
• Possibly a dash ("-"), dot ("."), and / or underscore ("_").
• Begin and end any "secret" word with an alphanumeric character, only. No leading or trailing dashes, dots, or underscores. Remember, the format of the Mail-to-Blogger address is "public.private@blogger.com" (and "private" is the "secret" word).
• No upper case letters, no special characters, and no non "Roman" alphabetic characters.

WikiPedia: Email address notes

Organizations are free to restrict the forms of their own email addresses as desired, e.g., Windows Live Hotmail, for example, only allows creation of email addresses using alphanumerics, dot (.), underscore (_) and hyphen (-).

If you want to use Mail-to-Blogger successfully, be conservative with the address.

The "secret" word is a password.
Passwords need to be complex, and non guessable.

• First, do not use details from your real life, like your social security number, street address, name of husband / wife, and so on. If you can remember it, the bad guys can - and will - guess it.
• Second, avoid words found in the dictionary of your native language. Dictionary based password guessing is a very popular technique, used by many hackers.
• 12 to 24 character random strings, combining lower case letters (26 character, "a" - "z"), and numbers (10 character, "0" - "9"), are best. It's your blog, just know the risks - and learn to live with the limitations. See WikiPedia: Password strength, for more details.
• See Blogger Help: Post via email, for general guidelines - but consider the password character limitations too.

You want any Mail-to-Blogger posts to be published, so keep the character set simple. You want Mail-to-Blogger to be secure, so keep it non guessable. Keep your blog under your control - but be able to publish to it, as necessary.