How Salesforge + ColdRelay Work Together
ColdRelay (Infrastructure)
ColdRelay provides the mailboxes Salesforge sends from. Each mailbox is a Microsoft 365 account on a dedicated, isolated Azure tenant with its own dedicated IP, fully-automated DNS (SPF, DKIM, DMARC), and a 95% inbox-placement guarantee. ColdRelay's pricing is per-mailbox: $1 (1-199), $0.85 (200-999), $0.70 (1K-4,999), $0.55 (5K+). Setup completes in 60 minutes, no warmup wait.
Salesforge (Sending Platform)
Salesforge is an AI-powered cold email sending platform — it generates personalized messages at scale, runs multi-step sequences with A/B testing, and ships Agent Frank, an AI SDR agent that drafts and sends prospect-specific outreach. By default, Salesforge sits on top of Mailforge infrastructure (its sister product), but it supports any custom SMTP/IMAP, which is what makes it pair cleanly with ColdRelay. You bring the mailboxes; Salesforge orchestrates the AI-driven sends across them.
Why use them together
Salesforge is the brain (AI personalization, sequences, Agent Frank, analytics). ColdRelay is the body (mailboxes, IPs, DNS). The combination gives you a clean separation: Salesforge handles campaign logic and AI-generated messages, ColdRelay handles infrastructure quality. Switching either side later is straightforward because they're loosely coupled — if you change sending platforms, the ColdRelay mailboxes still work; if you change infrastructure, Salesforge campaigns still work.
Connect Salesforge to ColdRelay (Step-by-Step)
- 1
Order ColdRelay mailboxes
Sign up at coldrelay.com/sign-up, pick a domain (ColdRelay handles registration for $14), and order your mailbox count. The minimum is 50 mailboxes ($50/month at the base tier). ColdRelay's automation provisions the dedicated mail server, registers the domain, and creates all mailboxes inside an isolated Azure tenant.
Note: Provisioning takes 60 minutes end-to-end. You'll receive a CSV with every mailbox's SMTP host, port, username, and password once it's complete.
- 2
Wait for DNS propagation
ColdRelay configures SPF, DKIM, and DMARC records automatically on the new domain. DNS propagation usually completes in under an hour but can take up to 24. You can verify with the Email Deliverability Test at coldrelay.com/tools/email-deliverability-test — when SPF, DKIM, DMARC, and MX all show as configured, you're ready.
Note: Don't start sending before all four records (SPF, DKIM, DMARC, MX) verify correctly. Sending before authentication is in place causes immediate spam-folder placement.
- 3
Connect mailboxes to Salesforge
In Salesforge, go to Mailboxes → Connect Mailbox → Custom SMTP/IMAP (not the default Mailforge option). For each ColdRelay mailbox, paste its SMTP host (box.YOURDOMAIN.com), SMTP port (587), SMTP username (the full email address), and the password from the ColdRelay CSV. Repeat for IMAP using port 993. Salesforge tests the connection and marks the mailbox as Connected once it validates.
Note: Salesforge's default flow steers you toward provisioning new Mailforge mailboxes inline. Skip that and pick Custom SMTP/IMAP — that's the path that uses your ColdRelay mailboxes instead.
- 4
Set daily limits per mailbox
In each Salesforge mailbox's settings, set the daily send limit to 2 outbound emails per day. This matches ColdRelay's per-mailbox cap (designed for optimal deliverability, not maximum volume). With 50 mailboxes you can send 100 outbound emails/day; 200 mailboxes = 400/day; 1,000 mailboxes = 2,000/day.
Note: Going higher than 2/day/mailbox is the single fastest way to degrade deliverability. ColdRelay's pricing model assumes 2/day — if you need 5,000+ emails/day, add more mailboxes, don't push existing ones harder.
- 5
Enable warmup in Salesforge
Turn on Salesforge's built-in warmup (Infraforge-powered) for each mailbox. Set the daily warmup limit to 2 emails and the reply rate to ~40%. Warmup ramps up the mailbox's reputation by exchanging emails with other mailboxes in the warmup network. Combined with 2/day outbound, total mailbox activity stays at 4/day — exactly ColdRelay's optimal-deliverability profile.
Note: ColdRelay mailboxes ship reputation-ready (the Azure tenant + dedicated IP isolation gives you a clean start) but warmup is still recommended for the first 2 weeks of active sending.
- 6
Configure your first campaign and Agent Frank
In Salesforge, create a campaign, paste your prospect list, define your sequence (subject lines + email bodies + follow-up cadence), and assign your ColdRelay mailboxes as the sending accounts. If you're using Agent Frank, give it your ICP definition and value-prop context — it will generate per-prospect personalized variants on top of your base sequence. Salesforge distributes sends across all assigned mailboxes respecting each one's daily cap.
Note: Agent Frank's personalization multiplies subject-line and body variations dramatically. That's a deliverability advantage (less mailbox fingerprinting) but watch token budgets — high-volume runs can rack up AI costs separately from your seat-based plan.
- 7
Monitor deliverability ongoing
Run the Email Deliverability Test weekly to verify SPF/DKIM/DMARC stay passing. Check Google Postmaster Tools for spam-folder rates and IP reputation. ColdRelay automatically monitors blocklists — you'll get an alert if any of your dedicated IPs hit a major blocklist (Spamhaus, Barracuda, SORBS, SpamCop).
Note: ColdRelay's 95% inbox-placement guarantee is contingent on following the 2/day/mailbox cap. Exceeding the cap voids the guarantee.
- 8
Iterate with Salesforge analytics
Salesforge's dashboard surfaces open rates, reply rates, and per-variant performance across Agent Frank's AI-generated messages. Use the reply-rate signal to prune underperforming variants and double down on the angles that land. The infrastructure stays constant — only the content evolves — so any rate movement is content-driven, not infrastructure-driven.
Note: Track per-domain reply rates separately. If one ColdRelay domain trends low while others trend healthy, that's a content-mismatch signal for that domain's persona, not an infrastructure issue.
Key Considerations for Salesforge + ColdRelay
Daily send limits per mailbox
Set Salesforge's per-mailbox daily limit to 2 outbound + 2 warmup = 4 total/day MAX. This is ColdRelay's optimal-deliverability cap. Going higher is the single biggest cause of mailbox burnout we see. Scale total volume by adding more mailboxes, not by pushing existing ones harder.
Pick Custom SMTP/IMAP, not the default Mailforge path
Salesforge's onboarding nudges you toward provisioning new Mailforge mailboxes inline. That's its native path. If you're bringing ColdRelay mailboxes, explicitly choose Custom SMTP/IMAP at the mailbox-connect step. The two products (Salesforge + Mailforge) are tightly coupled by default; ColdRelay slots in as an alternative infrastructure layer underneath the same Salesforge sending logic.
Dedicated IPs end shared-IP risk
Each ColdRelay mailbox is on a dedicated IP within your isolated Azure tenant. Other Salesforge users on shared infrastructure share IP reputation with random other senders — bad actors on the same IP damage everyone's deliverability. With ColdRelay your IP reputation is entirely your own.
Agent Frank pairs well with dedicated infrastructure
Agent Frank's AI personalization is content-heavy — every prospect gets a near-unique message. That's an inherent deliverability advantage (mailbox-fingerprinting filters can't pattern-match a near-unique message). Combined with ColdRelay's dedicated IPs and clean Azure tenant, you get strong content variety on top of strong infrastructure — the two reinforce each other.
Switching cost is low
If you decide Salesforge isn't right and want to switch to Instantly, Smartlead, or another sender later, your ColdRelay mailboxes work with any platform that supports custom SMTP/IMAP. You don't lose the infrastructure investment.
Domain-rotation strategy
ColdRelay caps each domain at 100-150 mailboxes for deliverability reasons. If you need 500+ mailboxes, you'll order multiple domains. Salesforge handles multi-domain campaigns natively — assign mailboxes from each domain to different campaign tracks (or different Agent Frank personas) to spread risk.
Pricing Snapshot
ColdRelay
ColdRelay's per-mailbox cost ranges from $1.00 (1-199 mailboxes) down to $0.55 (5,000+). Domain registration is $14/year, one-time. For 200 mailboxes: 200 × $0.85 = $170/month + $14 annual domain cost.
Salesforge
Salesforge pricing is tiered by seat count plus AI-credit consumption for Agent Frank generations. Plans scale with the number of active campaigns, AI personalization volume, and seat count. Current numbers are at salesforge.ai/pricing — the model favors teams running heavy AI personalization across many prospects rather than fixed per-mailbox cost.
Total monthly
A typical 200-mailbox cold email operation with Agent Frank running: ColdRelay infrastructure at ~$170/month + Salesforge mid-tier plan. At 1,000 mailboxes: ColdRelay $700/month + Salesforge higher-tier seat. Compare against Google Workspace at $6+/mailbox/month: 200 GW mailboxes alone would be $1,200/month before Salesforge's seat cost — and you'd still be on shared infrastructure.
Common Issues + Fixes
⚠ Mailbox-connect flow keeps trying to provision a new Mailforge mailbox instead of using your SMTP/IMAP credentials
You're on Salesforge's default path, which provisions Mailforge inline. Back out and choose Custom SMTP/IMAP at the mailbox-connect step explicitly. The Mailforge path doesn't accept external SMTP credentials — it's intended to bundle infrastructure into the same flow as the sending layer.
⚠ Warmup turned on in ColdRelay but not actually warming in Salesforge
Salesforge warmup runs through its own (Infraforge-powered) warmup network and must be toggled on per-mailbox inside Salesforge — turning it on at the ColdRelay layer doesn't enable Salesforge's warmup automatically. Open each mailbox in Salesforge, enable warmup, set the daily limit to 2 and reply rate to ~40%.
⚠ Emails landing in spam at Gmail
Run the Email Deliverability Test against the domain. If SPF, DKIM, or DMARC fails, the records may not have propagated yet — wait 24 hours. If they all pass, check Google Postmaster Tools for the domain. The most common cause of post-authentication spam placement is exceeding the 2/day/mailbox cap in Salesforge or running an Agent Frank prompt that drifts into spammy phrasing.
⚠ Agent Frank generations triggering spam filters despite clean infrastructure
AI-personalized messages can sometimes drift into spam-trigger phrasing (excessive urgency, certain financial keywords, link density). The infrastructure is doing its job — SPF/DKIM/DMARC pass and IP reputation is clean. Refine Agent Frank's prompt and guardrails, and run the CAN-SPAM Checker at coldrelay.com/tools/can-spam-checker on sample outputs to catch problem phrasing before it ships.
⚠ Salesforge's reply tracking shows no replies even though prospects are replying
Salesforge polls IMAP on port 993 with TLS. Verify the IMAP credentials match the ColdRelay CSV. Most commonly: the IMAP password is the same as the SMTP password but it can drift if a mailbox was reset. Re-test in Salesforge's mailbox settings (Test Connection button).
Frequently Asked Questions
Do I need ColdRelay if I already have Salesforge?
Salesforge is a sending platform — by default it ships with Mailforge infrastructure underneath, but you can swap in custom SMTP/IMAP. Most Salesforge users who want stronger deliverability isolation switch the infrastructure layer to ColdRelay: dedicated Azure tenant, dedicated IPs, automated SPF/DKIM/DMARC, and a 95% inbox guarantee at $0.55-$1.00/mailbox/month.
Why use ColdRelay instead of Salesforge's default Mailforge infrastructure?
Mailforge is Salesforge's built-in infrastructure layer — convenient because it's bundled, but it's the same tradeoff every bundled-infra sender makes. ColdRelay gives each customer a fully-isolated Azure tenant with dedicated IPs (no shared reputation), automated DNS, M365 mailboxes, and a 95% inbox-placement guarantee. For teams that care about deliverability independence and want infrastructure decoupled from the sending platform, ColdRelay is the upgrade.
How many mailboxes do I need to scale to my target send volume?
ColdRelay's per-mailbox cap is 2 outbound emails/day for optimal deliverability. So if you want to send 1,000 emails/day, you need 500 mailboxes. The Mailbox Calculator at coldrelay.com/tools/mailbox-calculator lets you input your target volume and gives you the exact mailbox count + pricing tier.
Does Agent Frank work with ColdRelay mailboxes?
Yes. Agent Frank is part of Salesforge's campaign-orchestration layer — it generates personalized messages and feeds them into the send queue, agnostic to what infrastructure sits underneath. As long as your ColdRelay mailboxes are connected via Custom SMTP/IMAP, Agent Frank uses them just like any other connected mailbox.
Will my Salesforge campaigns break if I switch from Mailforge to ColdRelay mid-flight?
No. Switching infrastructure providers mid-campaign means reconnecting each mailbox in Salesforge (new SMTP/IMAP credentials), but campaign logic, sequences, Agent Frank prompts, A/B tests, and contact lists stay intact. The transition takes a few minutes per mailbox. We recommend pausing campaigns during the swap to avoid any deliverability blips.
Can I use ColdRelay with a free Salesforge plan?
Salesforge's pricing tiers are at salesforge.ai/pricing — the entry tier is workable for a small ColdRelay setup (50-100 mailboxes), but the combination really pays off at higher mailbox counts where Agent Frank's AI personalization across many prospects becomes the differentiator. ColdRelay's 50-mailbox minimum sets the floor on the infrastructure side.
What if Salesforge's deliverability is bad with my ColdRelay mailboxes?
That's almost always a campaign-content issue (Agent Frank prompts drifting into spam-trigger phrasing, link density too high, sender names looking off) rather than an infrastructure issue. ColdRelay's 95% inbox guarantee means the infrastructure is doing its job. Use the CAN-SPAM Checker at coldrelay.com/tools/can-spam-checker and the Subject Line Generator to validate generated content. ColdRelay's deliverability consultant (included at higher volumes) can help diagnose.