Both iCloud and Zoho free tier were good options to park one's custom domain for email. Both services support security features like SPF and DKIM, without which

Both iCloud and Zoho free tier were good options to park one's custom domain for email. Both services support security features like SPF and DKIM, without which you may experience bounced email due to the spam filter on receiving sides. Eventually I picked Zoho because it supported catch-all email account, and its instruction to set up DNS records were easy to follow too. I used Namecheap for domain transfer, and found its support responsive. For example, I found that I could immediately resubmit transfer request with its refund, after I failed the first transfer attempt due to GoDaddy's "protection" measures. For old emails, Google Takeout let you download a mbox file that you can easily open on Mozilla Thunderbird. Takeout also downloaded all your content in Photos and Drive etc that you can keep offline. Now that I don't have a custom domain associated with my G Suite account, I can sit back and let Google do its things. Overall, on positive note, this was a good excuse to learn about / brush up one's knowledge on domain transfer, DNS records (MX/TXT/CNAME), SPF/DKIM email security, mbox import.