We use Confluence for this purpose. Some investment is required in building a template to capture the requirements from different stakeholder groups' points of view but this can be evolved over time.
Anyone can access (with appropriate read/edit rights) at any time so good for fostering collaboration.
We encourage stakeholders to update the information and ...
I use Proton Mail, which is a secure mail service. For paid contributors, they offer the ability to link the DNS record of a domain that I own to their system, so that I can use the proton mail system as "the official" mail for that domain.
This means that sending email to my_address@my_personal_domain.tld results in the mail appearing in my ...
My obligatory Python based answer.
Given the requirement not to use a data collection company (there are a lot of them out there) and that most if not all of the free SMS sending services are run by some of them you need something that can:
Check your emails
Run some filters on them (presumably you don't want spam notifications)
Send the SMS
I would ...
Here is another alternative - Zoho Mail.
It can do catch all and forwarding.
All the pricing plans are lower than your current subscription of 6,5EUR.
(Note: They also have a free plan, but it does not support forwarding.)
There are domain registrar that provide the email catch all and forwarding service that is included in the domain registration fee or as an add on fee.
I assume you are now paying domain name registration fee (yearly) + GSuite fee (monthly). So it might lower your cost if you transfer your domain to such registrar. (Assuming you can/want to do that.)
If you ...
Sender tool can help to create own HTML email design for subscribers and send it to your subscribers. You can use segmentation to send different emails for every product or you can use your data and import that. Sender have ease to use drip drop builder and ready-to-use templates.
Sender have integrations with Wordpress + Woocommerce, Magneto or Prestashop, ...