Understanding Email Campaigns

Weekly around 10-15 emails land in my inbox, selling me some SaaS tool or the other. Most of them seem to offer solutions to problems I didn't even know existed, so I rarely engaged with them.

So last week, I decided to run a small experiment, taking time to read the emails, visit their websites, and understand their offerings better.
Out of 25 odd emails that landed, I found 12 made sense, who I researched further.
My goal was simple:
• See what type of messaging makes sense
• How companies respond to queries

I have been contemplating email campaigns later this year, so I figured I'd evaluate from a customer viewpoint before starting.

After reviewing each tool, I sent an email explaining:
• Why it didn't make sense for my business
• What features and pricing would actually make sense
• Asked 3 companies for further proof on their claims

Now out of 12 emails sent, 8 responded back:
• 6 firms just said thanks and moved on - basically marking me as someone who doesn't fit their customer profile
• 1 replied sharing same info again when I asked for more proof (which was funny since I'd already stated I reviewed that)
• Finally 1 firm's founder responded explaining what they're building, understood I may not be their customer currently, but still requested a call to understand my business better

This clearly highlighted that for email campaigns to actually work, you face multiple hurdles:
• Email doesn't land in spam
• Person actually opens the email
• Marketing message convinces them to read fully or visit website
• Finally they get curious enough to ask for a call
• Only then do they become a real prospect

That's a lot of "ifs" and needs serious thinking and experimentation to actually undertake such an endeavor myself. A lot is spoken about email marketing, but it still feels overwhelming for anyone starting out.

I would certainly appreciate some advice from others on their experience with B2B email outreach - either sending or receiving, to help me learn from real examples.