Hello, Im using ISPConfig with PMG and my emails landing in SPAM by gmal, yahoo... SPF, DKIM, DMARC are ok. Does anyone have any idea? if i send mail directly from ISPConfig i have the problem too.
This was discussed before and you can search the forum for its exact answer. What I remember is it is best to let ISPConfig managed it directly instead of using PMG. Any problem with ISPConfig, you can ask in here while providing the necessary required info for us to help.
It might just be that your IP has a bad reputation at Google, Google has its own lists of IP addresses, and having valid DKIM and DMARC does not guarantee that your emails go through. What you might want to do is to sign up at the Google postmaster website if you have not done that yet. Also, some of the sending domains can have bad reputations, it's often enough that a few people that received mails from you have put the emails into their spam folder to affect your whole mail system negatively.
You should definitely check with mail-tester site etc, to make sure your mail is ok in itself. However with these big providers it is very hard to find out what the cause is that some mails are flagged as spam and other are not. I can give you an example from our mailservers, we have around 500-600 maildomains that send mail through our smtp server at the moment. Most mails seem to be completly fine and get accepted by gmail for example, however there is one customer that reported that all mails get flagged as spam by google, it does not matter what the content of the mails are, nor does it matter which mailbox sends these mails. Note that this domain has valid SPF like others and sends through the same mailserver. So it can be quiet annoying to deal with these kind of issue, cause you will not get any information as of why these spamfilters start flagging these mails.
We use ISPConfig with PMG as well, however PMG only to receive mail. For sending mail, we use Amazon SES. Its pretty easy to configure ISPConfig to relay mail via Amazon SES. Amazon SES tends to be ok with most mail providers, like Google, MS etc.
