One of the useful tools to resolve this issue would be e-mail headers. Often they can reveal WHY that e-mail went to spam folder. E-mail headers contain full information on what happened to e-mail while it was in transit. Often you will be able to see results of anti-spam processing which was done on the e-mail. And often it is full report which can tell you why this e-mail was considered as spam by that software.
In this example we can see header X-Spam-Status:
which set to score=3.7
. This header is just information that anti spam software analyzed the e-mail and based on the settings it has made the decision that this e-mail has spam score 3.7
It is semi-arbitrary scale and amount of spam points which e-mail will get depends on the software.
Here is another example:
X-Spam-Status: Yes, hits=27.3 required=5.0
tests=AS_SEEN_ON,BASE64_ENC_TEXT,CLICK_BELOW,CLICK_BELOW_CAPS,
CLICK_HERE_CAPS_LINK,CLICK_HERE_LINK,CTYPE_JUST_HTML, DCC_CHECK,
DIET,FOR_FREE,HAIR_LOSS,HGH,HIDE_WIN_STATUS, HTML_COMMENT_UNIQUE_ID,
HTML_WITH_BGCOLOR,JAVASCRIPT_UNSAFE, OBFUSCATING_COMMENT,
OPT_IN,RAZOR2_CHECK,RCVD_IN_DSBL, REVERSE_AGING,SPAM_PHRASE_05_08
version=2.43
X-Spam-Flag: YES
X-Spam-Level: ***************************
Here we can see that e-mail was evaluated to have 27.3 spam score (hits=27.3
). This software was configured to consider any e-mail with score more than 5 to be spam (required=5.0
). So what it does in this case? It sets flag X-Spam-Flag
to YES
. This is just evaluation. Now you can set filter on your e-mail client which will put any e-mail with X-Spam-Flag: YES
to the spam folder.
I just gave you one example of how e-mail headers work. Probably you will be able to see reason why your e-mails are considered to be spam.
Ask people who receive your e-mails to send you back e-mail headers for research. Every modern e-mail client should be able to get those.
I am not promising it will work for you. But e-mail headers and server logs - are first things you should look at while resolving e-mail issues.