Twitter accepts accounts talking about Bitcoin.
They are most definitely banning Bitcoin-based accounts it seems. (When they pwn your account, they don't tell you why.)
I saw threads posted by OP himself related the so-called ban of crypto/bitcoin-related accounts about
ConstantContact and
SendInBlue. But upon searching in google, I didn't see any article related to this except for the mailchimp which I mentioned already.
I spoke with Constant Contact over the phone. You can call them as well (866) 289-2101.
SendInBlue:
"
Hello ____,
Thank you for contacting us about your account, and for taking time to give SendinBlue a try.
Each new account is reviewed by our team before campaigns can be sent out. We do this to ensure new users comply with our terms of service, and are in a position to be successful using SendinBlue. After reviewing your account and the nature of your content, unfortunately we will not be able to validate your account.
We apologize for the inconvenience and want to let you know that this is not a judgement on your business. Rather, we've tried working with similar clients in the past and have found that you will experience unsatisfactory results.
If you have made a purchase, we have cancelled any future renewals and refunded any unused credits. This refund will be processed back to your original form of payment and should appear on your statement within the next 1-2 weeks. However, if you do not see the credit within that timeframe please let us know by responding to this message.
We appreciate that you took the time to try our service and do wish you the best.
Please let us know if you have any questions.
Kind regards,
_____
SendinBlue Customer Service"
For FreeBitcoins.com... maybe it was an us thing and not a crypto thing, BUT in the email they said not a judgement against our business, but the crypto scene.
I imagine a lot of these email services get a bad taste in their mouth due to emails being sold on the dark web and ICO / altcoin fucktards.