It’s important not to confuse email marketing best practices, and email best practices in general, with email “common practices”.
In fact, this can be a very dangerous, slippery slope on which to pin your email deliverability and indeed your email reputation. In fact at one point in time there was a meme going around suggesting exactly that, that it’s “important to follow email marketing common practices.” No, no, NO! To suggest that best practices aren’t really best practices, but only ‘common practices’, reduces them to “not necessarily required” practices.
It also suggests that common practices that others do are acceptable practices, when we all know that often they are not. Case in point: Lots of email senders still put people on their mailing lists without consent, some even purchase lists of email addresses, which would suggest that it is a “common” practice. However, it is absolutely not acceptable to do that, and it is definitely not a best practice. In fact, it’s a “worst practice”.
So make no mistake: as far as those receiving and delivering your email are concerned, there are very definitely “best practices”, and they want you to follow them if you want them to accept and deliver your email.
There are other “common practices” are not best practices at all. For example, it’s surprisingly (shockingly, in fact) common for otherwise legitimate email senders to not remove from their mailing lists email addresses which are bouncing in a timely manner – if at all.
However, anybody who thinks that removing bouncing addresses is a “nice thing to do”, and not a best practice, is sadly mistaken. They would be similarly mistaken to think that they can ignore it as a best practice and not suffer the consequences.
Reducing what have finally become acknowledged as best practices (such as using confirmed or double opt-in, responsible bounce handling, and instant removal from lists of those requesting to be unsubscribed) to something which appears to have less authority about it (“common practices”) may make senders feel better about not doing these things, but it doesn’t change that they are generally accepted best practices in the email industry, and particularly by email receivers such as inbox providers, ISPs and spam filters as, well, best practices.
This all means that if you choose not to follow these best practices, well, caveat sender. You may get away with it, but you are much more likely to find that your email starts going to the junk folder more and more often.
And when that happens, and when an ISP demands proof that a subscriber complaining that you are spamming them actually subscribed (which is where COI sure comes in handy), or when the inbox provider tells you that you are being dinged because you continue to send email to addresses that are bouncing, try responding with “but those are just common practices, not best practices.”
Then let us know how it works for you.