Send mail from @sponicgardens.com via Gmail

How the round-trip works

Both legs are already wired at the infrastructure layer. This doc only covers the per-Gmail-account "Send mail as" step.

One-time setup per alias

1. Grab the Resend SMTP credentials

Resend exposes a single SMTP endpoint that any verified-domain address can send through. From Bitwarden (folder devops-sponic):

• Item: Resend — Sponic Gardens Email (id 87184c25-8884-497c-94d2-b41600586a6e)
• Use the API Key (Sending Only) custom field — the sending-only key is safer to paste into a Gmail box than the full-access key. The full-access key is fine if that's what you already have handy.

export BW_PASSWORD=$(security find-generic-password -a "[email protected]" -s "bitwarden-cli" -w)
SESSION=$(/opt/homebrew/bin/bw unlock --passwordenv BW_PASSWORD --raw 2>/dev/null)
/opt/homebrew/bin/bw get item 87184c25-8884-497c-94d2-b41600586a6e --session "$SESSION" \
  | jq -r '.fields[]|select(.name=="API Key (Sending Only)").value'

2. Add "Send mail as" in Gmail

In the Gmail account that receives mail for this alias (today: [email protected]):

1. Open Settings → Accounts and Import.
2. Under Send mail as, click Add another email address.
3. Fill in:
   • Name: the display name you want recipients to see (e.g. "Rahul Lio").
   • Email address: the alias, e.g. [email protected].
   • Leave Treat as an alias checked.
4. Click Next Step. Gmail asks for SMTP credentials. Enter:

   SMTP Server	smtp.resend.com
   Port	587
   Username	resend (literal string, not your email)
   Password	your Resend API key (from step 1)
   Secured connection	TLS (STARTTLS) — the default on port 587

5. Click Add Account. Gmail sends a verification code to the alias.

3. Confirm the verification code

Cloudflare Email Routing forwards the code from [email protected] back to [email protected] — usually within seconds. Open the message, click the confirmation link or copy the code into the still-open Gmail dialog. Done.

4. Make it the default for this alias (optional)

Back in Settings → Accounts, you can:

• Click make default next to the alias if you want every new compose to default to it.
• Or leave the personal address as default and select the alias per-message via the From dropdown in the compose window.
• Set "When replying to a message: Reply from the same address the message was sent to" — this is what makes replies to [email protected] automatically come from [email protected].

Send a test message

1. Compose a new mail in Gmail. In the From dropdown, pick the alias.
2. Send to a different mailbox you can check (not the same Gmail — see the gotcha below).
3. Confirm the recipient sees From: Rahul Lio <[email protected]>.
4. Hit reply on the recipient side. The reply should land back in [email protected] within a minute.

Repeat for additional aliases

One Send mail as entry per alias. Re-run steps 2–3 for each one:

• [email protected]
• [email protected]
• [email protected]
• …etc.

Same SMTP host / port / username / password every time — only the address and display name differ. The verification email always lands in the same Gmail inbox because the catch-all on sponicgardens.com forwards everything to [email protected].

If a collaborator wants to send from their own Gmail

The same flow works in any Gmail account. Add the collaborator's address as a destination in Cloudflare Email Routing first (they'll get a CF verification email), wire a forwarding rule to them, then they repeat the Send mail as setup in their Gmail using the same Resend SMTP creds.

Limits and caveats

• Resend free tier: 3,000 emails/month, 100/day. Plenty for personal correspondence; bump the plan if a real send-blast lands in scope.
• From address must be on a Resend-verified domain. If you try to send from [email protected] (the deprecated single-s domain) after verification is moved to sponicgardens.com, Resend will reject the message at SMTP time.
• One sending identity per Gmail "Send mail as" entry. Aliases don't auto-fan out; each one needs its own entry.
• Replies require the inbound chain to be intact. If you remove the sponicgardens.com catch-all in Cloudflare, replies disappear silently — outbound still works, but you'll never see the answers.
• Display name shows what you set in Gmail, not what's on the Resend account. Pick something the recipient will recognize.

Troubleshooting

Doc owner: Rahul. Last updated 2026-05-03. Related infra: Cloudflare Email Routing on the wingsiebird account, Resend domain sponicgardens.com (id 36395b8c-d435-4f8a-8049-7fa828607a12).