TL;DR
Custom SMTP in Plutio lets freelancers and agencies route all outgoing workspace emails, including invoices, proposals, contracts, notifications, and payment receipts, through their own email server so every message sends from their domain instead of Plutio's.
Plutio supports two connection methods: an integrated account (connect a Gmail or Outlook inbox directly via OAuth) or a custom SMTP configuration where the sender enters the host, port, username, password, SSL toggle, sender email, and sender name. Over 40 pre-configured email services are available in the dropdown, including Gmail, Outlook365, Amazon SES, SendGrid, Mailgun, Postmark, and Zoho. The practical result: a client receiving an invoice sees hello@yourstudio.com in the sender field instead of a platform-generated address, and that consistency carries through every email Plutio sends on behalf of the workspace.
Custom SMTP is part of Plutio's white-label add-on at $9/month on Core ($19/month) and Pro ($49/month) plans, included free on Max ($199/month). Configuration takes under 5 minutes in Settings > Interface under the Sending Email Connection section. A 7-day free trial includes access to all white-label features.
What custom SMTP is
Custom SMTP is the ability to configure an external email server as the sending gateway for all outgoing workspace emails, replacing Plutio's default mail servers with a connection that sends from a domain owned by the business.
SMTP (Simple Mail Transfer Protocol) is the standard protocol email servers use to send messages. When a freelancer configures custom SMTP in Plutio, every outgoing email, whether it is an invoice notification, a proposal delivery, a contract signature request, a payment receipt, or a general workspace notification, routes through that configured server. The recipient sees the freelancer's domain in the "from" field, and the email passes SPF, DKIM, and DMARC checks against that domain rather than against Plutio's infrastructure.
Integrated account vs custom SMTP
Plutio offers two tabs for sending email configuration. The Integrated Account tab connects a Gmail or Outlook inbox via OAuth, so emails send directly from that inbox's address without entering any SMTP credentials manually. The Custom SMTP tab exposes the full configuration form: a service dropdown with 40+ pre-configured providers (Gmail, Outlook365, Amazon SES, SendGrid, Mailgun, Postmark, Zoho, FastMail, and more), plus fields for host, port, SSL/TLS toggle, username, and password. Selecting a service like Gmail auto-fills the host (smtp.gmail.com) and port (465) with SSL enabled, so the only manual entry is the login credentials.
Reply-to notification domain
Beyond the sender address, Plutio includes a reply-to notification domain field. The reply-to notification domain field sets the domain used in reply-to headers for notification emails, so when a client hits "reply" on an invoice notification or a contract delivery, the response routes to the correct inbox on the freelancer's domain. Combined with the sender address, both the "from" and "reply-to" fields show the business domain rather than a platform address. The key detail: custom SMTP affects every outgoing email Plutio sends on behalf of the workspace, not just invoices or proposals. Notifications, reminders, receipts, and contract signature requests all route through the configured server.
Clients used to ask if my invoices were legitimate because they came from a plutio.com address. After setting up custom SMTP with my own domain, payment response times dropped by about two days on average.
Why custom SMTP matters for freelancers
Emails sent from a platform's default servers create a branding disconnect at the exact moment a client is deciding whether to pay an invoice, sign a contract, or approve a proposal. A $5,000 proposal arriving from noreply@platform.com instead of proposals@yourstudio.com introduces doubt before the content is even read. Email deliverability also takes a hit: shared sending domains used by thousands of platform accounts carry higher spam risk than a dedicated business domain with properly configured SPF and DKIM records.
The cost is measurable. Emails flagged as promotional or routed to spam folders delay payments by days. On a $3,000 invoice with net-15 terms, a 3-day delay from a spam-filtered payment notification pushes cash flow back almost a week. Across 10 active clients, those delays compound into $10,000 to $30,000 in outstanding receivables at any given time, all because the sending domain did not match the business.
HoneyBook sends all client-facing emails from HoneyBook's own domain on the Starter ($16/month) and Essentials ($32/month) plans. Custom email sending is only available on the Premium plan at $66/month billed annually, and even then HoneyBook uses its own infrastructure rather than allowing a direct SMTP connection. Dubsado sends emails from Dubsado's servers on all plans ($20/month and $40/month) with no custom SMTP option at any price point. FreshBooks has no custom SMTP configuration and sends all invoice and payment notifications from FreshBooks-branded email addresses.
The most damaging consequence is not a branding issue but a deliverability one. Shared sending domains used by thousands of accounts carry collective reputation, so one bad actor on the same IP range can push legitimate invoice emails into spam folders across the entire platform's user base.
Plutio's custom SMTP sidesteps shared sending infrastructure entirely. Emails route through the freelancer's own server, so deliverability depends on the business domain's reputation, which the freelancer controls directly through proper DNS configuration.
How custom SMTP works in Plutio
Open Settings, navigate to Interface, find the Sending Email Connection section, choose between the Integrated Account tab or the Custom SMTP tab, enter credentials, and all outgoing workspace emails start sending from the configured domain.
Before starting, make sure the email domain has SPF and DKIM records configured with the SMTP provider. Most providers (Gmail, SendGrid, Amazon SES, Mailgun) include setup guides for DNS records. DNS configuration happens outside Plutio, in the domain's DNS settings.
Step by step
- Step 1: Open Settings in Plutio and navigate to the Interface section. Scroll to the Sending Email Connection area, which has two tabs: Integrated Account and Custom SMTP.
- Step 2: Choose a connection method. For Gmail or Outlook, use the Integrated Account tab and click the connect button to authenticate via OAuth. For any other provider, switch to the Custom SMTP tab.
- Step 3: On the Custom SMTP tab, select a service from the dropdown (Gmail, Outlook365, Amazon SES, SendGrid, Mailgun, Postmark, Zoho, or any of the 40+ supported providers). Selecting a provider auto-fills the host and port fields. Enter the sender email address, sender name, username, and password. Toggle SSL on or off depending on the provider's requirements.
- Step 4: Optionally, set the reply-to notification domain so client replies route to the correct inbox on the business domain.
- Step 5: Click the submit button. Plutio validates the connection and confirms success. A "Send test email" option appears after connection to verify delivery. All outgoing workspace emails now route through the configured SMTP server.
Practical tip: after connecting, send a test email and check that it arrives in the inbox (not spam). If using Gmail SMTP, make sure to use an App Password rather than the regular Gmail password, since Google requires app-specific passwords for third-party SMTP connections.
Who needs custom SMTP
Freelancers and agencies billing clients directly through Plutio, sending proposals and contracts for signature, and delivering project notifications, all from a business domain they want clients to recognize and trust.
A freelance brand designer sending a $4,000 proposal from proposals@janestudio.com creates a different first impression than the same proposal arriving from a generic platform address. The client sees the designer's domain in the sender field, in the reply-to header, and in the email footer, and that consistency reinforces the professional positioning that the proposal content is built around. Custom SMTP costs $9/month as part of the white-label add-on, and combined with connected domains and custom branding, the client experience is fully branded from the first email to the final receipt.
Agencies with 5+ team members sending invoices, contracts, and project updates to 20+ active clients each month benefit from domain-level deliverability control. Shared platform sending domains carry collective spam risk across all users, so an agency sending 200+ emails per month through Plutio's default servers depends on every other Plutio user's email behavior for deliverability. Custom SMTP moves that dependency to the agency's own domain, where the reputation is controlled internally. Over 35% of Plutio workspaces on Pro and Max plans configure custom SMTP within the first month of activating the white-label add-on.
Freelancers researching HoneyBook alternatives often discover that HoneyBook restricts custom email sending to the Premium plan at $66/month billed annually, with no direct SMTP connection option even at that tier. Freelancers comparing Dubsado alternatives find that Dubsado has no custom SMTP on any plan. Plutio includes custom SMTP as part of the $9/month white-label add-on on any base plan starting at $19/month, making it accessible at a fraction of the cost.
Bottom line: any freelancer or agency sending client-facing emails through Plutio, whether invoices, proposals, contracts, or notifications, gets better deliverability, stronger brand consistency, and full sender control by routing through custom SMTP.
