I currently have a very large list of user emails (around 100K), but with unverified emails addresses. In order to make signing up and using the site as convenient as possible (especially for the mobile apps), I did not require email verification.

I am running a last-effort fund-raiser for my site, and I would like to contact those users (because they would be the most interested in helping with the fund-raiser). Is there an optimal way to do this?

  • 1
    Are you asking how to contact those users? Or about the implications of doing so?
    – John Conde
    Commented Jul 29, 2014 at 1:02
  • I'm asking if there's an optimal way of contacting these users, avoiding any spammy repercussions.
    – mrl
    Commented Jul 29, 2014 at 1:07

1 Answer 1


Well, this is risky but the best thing you can do is make yourself look as un-spammy as possible. Following the Can Spam Act guidelines is a good place to start:

Unsubscribe compliance

  • A visible and operable unsubscribe mechanism is present in all emails.
  • Consumer opt-out requests are honored within 10 business days. [7]
  • Opt-out lists also known as Suppression lists are only used for compliance purposes.

Content compliance

  • Accurate from lines (including "friendly froms")
  • Relevant subject lines (relative to offer in body content and not deceptive)
  • A legitimate physical address of the publisher and/or advertiser is present. PO Box addresses are acceptable in compliance with 16 C.F.R. 316.2(p) and if the email is sent by a third party, the legitimate physical address of the entity, whose products or services are promoted through the email should be visible.
  • A label is present if the content is adult.

Sending behavior compliance

  • A message cannot be sent through an open relay
  • A message cannot be sent without an unsubscribe option.
  • A message cannot be sent to a harvested email address
  • A message cannot contain a false header
  • A message should contain at least one sentence.
  • A message cannot be null.
  • Unsubscribe option should be below the message.

Using a third party service like Constant Contact will take care of much of this for you (after an initial configuration). They also won't do things like send it all from the same server and do other good technical things that help prevent mail from being considered spam.

  • Thanks John. I definitely am not going to do this myself (currently using Mail Chimp). I was thinking about sending a verification email, but that act itself is going to be sending email to unverified emails. Would using a 3rd party service (like Constant Contact), still entail a level of risk because of the large unverified email list?
    – mrl
    Commented Jul 30, 2014 at 3:04
  • If I follow all the Can Spam Act guidelines, and use a third party service, is there a still considerable risk?
    – mrl
    Commented Jul 30, 2014 at 3:06
  • 1
    There's going to be some risk but by following best practices you will definitely minimize them. If you're really on the up-and-up, especially if this is just a one-time event, then you should be ok. The fact that these users signed up for your website means the vast majority of the emails will be legit and the users will probably recognize you and keep complaints to a minimum anyway.
    – John Conde
    Commented Jul 30, 2014 at 3:12

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