I have a few questions about aspects of email marketing.
I am using my own mail system rather than a ConstantContact-type operation.
Does it matter whether I send using phpMailer or SMTP?
My logic is that authenticated SMTP sending from a valid email address should help to keep the spam score low.
Does it matter if I link the images or embed them - in terms of spam score?
Does anyone have a recommendation for free or cheap software to process bounced emails and create a list of addresses to remove from my subscriber list?
While you can definitely optimize your emails what you will discover is that providers exist for a reason – to save you time, lots of time. Getting email out a few messages at a time is not a big deal but if you start sending tens of thousands or more ISPs notice and getting everything right is essential.
SMTP or sendmail don’t make the differance, what does matter is that all your settings line up. You need your IP to match the domain in a reverse lookup. Be sure all mail relays are closed. Be sure your sends are coming from the same return address. Check that your ip, your ip class, the ips near it aren’t blacklisted. Get white listed. Keep a constant optout policy and monitor everything frequently… if you see your aol open rate drop, contact aol, if you see your bounces increase, check your ip, etc.
if you are sending emails to the list from your own setup make sure you have some authentication installed like dkim or spf. YOu can also check to make sure your domain is kosher when it comes to reputation. take a look at senderscore.org to get some idea.
Normally links increase your spam score. There are quite a few spam words like " buy now", free etc… which increases your spam score. mailchimp has a service (paid) where they will run your newsletter to calculate spam score for it. It might be worth the money if you have a decent size list.
If you decide to send on your own make sure to not send too many too fast. Add some interval between each emails.
Ask your recipients to add the sender email on their address book, that would reduce the possibility of getting email to junk folder.
If I am not mistaken, PHPmailer uses authenticated SMTP to send email…
I don’t think it matters what you use so much as how you use it. You might get flagged for spam based on heuristics too, so make sure that you are not sending too many emails too quickly.
Personally, I would make sure that everyone receiving my newsletter actually wants to receive it by way of not using any “tricks” to get emails on your list and by making the unsubscribe easy and clearly marked.