Emails sent but not received

Question: Hello,

myself and others on my team are having difficulty sending emails. There doesn’t seem to be an error message on delivery but no emails are being received. Can you help investigate?

Answer: I recommend you to read the following page: My message never arrives despite it says it was delivered.

Even when you send a legitimate email message there are great chances it will be checked by your server, the recipient server, or both of them. Nowadays it is a common practice for system administrators to use spam checking and anti-virus software directly on their email servers. The idea is to eliminate or reduce the relaying of spam messages and the spreading of viruses thru the emailing system. On one hand, checking messages at the server level can drastically reduce the amount of junk that will end up in your mailbox but on the other hand, that system is far from being perfect and as a result, legitimate emails will also get caught and will never get delivered. Such messages are called "False Positives". On average, 15% of legitimate messages do not get through to the inbox because of the false positive problem, and the rate is increasing along with the volume of spam.

More information on this topic is available here: How to avoid a message from being flagged as spam.

Make sure your message content is not 'suspect' and doesn't look like spam:
- Avoid phrases and wording spammers commonly use.
- Avoid using all upper-case words in the message subject.
- Do not use (too) many images.
- Properly balance the size of your pictures with the text size.
- Avoid using HTML tags that could increase your spam score, e.g. iframe tags, multiple large font tags, and/or color font tags (better use inline CSS styles instead).
- Avoid using scripts in your messages, like javascript, VBScript.
- Correct any HTML coding errors in your messages, since these too will increase your spam score.