Mass E-Mail Marketing Software or Solution

I'm looking for a mass e-mail marketing software or solution. The e-mails I want to send will be mostly promotional or transactional to offer my products like electronic hardware or cars in nature. I'm not certain if I need an e-mail scheduler just yet, but I might so I'm open to options. Moreover, At the moment I think I don't need any custom website integrations as this time but if you think I can later integrate into an Webshop or an E-Commerce Plattform would be great. Would be great to get suggestions for a reliable and cost-effective solution.