We’re pleased to announce the 2026 SOLO Server Annual Release (1.26.1.0), which includes all improvements from our recent point releases, including 1.25.1.5 (March) and 1.25.1.6 (April). Together, these releases deliver a major new payment integration, expanded FastSpring Contextual store support, new email sender controls, and a number of smaller fixes and improvements.

Stripe and Stripe Partner Connect Integration

SOLO Server’s eCommerce capabilities now include support for Stripe, one of the most widely used payment processors in the world, alongside support for Stripe Partner Connect for authors who work with a Stripe partner platform.

This is a meaningful addition for authors taking advantage of SOLO Server’s integrated eCommerce, where licensing and payment processing live in the same system. License generation, fulfillment emails, the Customer License Portal, and renewal workflows all operate cohesively, with no synchronization required between separate platforms. Customers can use Stripe to purchase new licenses, upgrades, and renewals through the SOLO Server shopping cart and Customer License Portal.

A few of the benefits this opens up:

• A modern, on-page checkout experience. With Stripe, customers complete payment directly within the SOLO Server shopping cart page rather than being redirected away to a separate payment site. This keeps the checkout flow on your storefront from start to finish — a smoother experience for customers and a more cohesive look for your brand. (For authors currently using our PayPal Standard integration, where customers are redirected to PayPal to complete payment, Stripe represents a nice step forward in checkout experience.)
• Direct access to Stripe’s payment ecosystem, including its global card coverage, fraud tooling, and broad set of alternative payment methods.
• Stripe Partner Connect support for authors operating under a partner platform arrangement, allowing payments to flow through the partner’s Stripe account.
• No change to SoftwareKey’s eCommerce fees. Authors who move to Stripe will see the same SoftwareKey eCommerce fee structure they’re used to — the choice of payment processor is yours to make based on what works best for your business.

A note on recurring billing: the initial Stripe integration supports one-time payments. Automatic recurring billing through SOLO Server’s payment plans feature is on the roadmap for a future release.

This is a significant addition to SOLO Server’s eCommerce options, and it deserves a deeper look than we can fit here. Watch for a dedicated blog post that walks through the Stripe integration in detail and the specific scenarios where it shines.

FastSpring Contextual Store Enhancements

Several improvements have been made to SOLO Server’s FastSpring integration, with a focus on FastSpring’s newer Contextual store platform. The most significant of these expands the licensing approaches available to authors using FastSpring as their eCommerce server.

More Flexibility in How You Control Subscription Licenses

In our blog post on Two Ways to Control Subscription Software Licenses, we describe two approaches that licensing and eCommerce systems can use together to enforce subscription terms:

• Approach 1: Expiration Date — the eCommerce system extends the license’s expiration date each time a successful subscription payment is processed.
• Approach 2: License Status — the eCommerce system updates the license status to active or voided based on payment success or cancellation, without using a specific expiration date.

Previously, SOLO Server’s FastSpring integration could only update the License Status field, which meant FastSpring authors were effectively limited to Approach 2. With the addition of the subscription.charge.completed Webhook for FastSpring Contextual stores, Approach 1 is now also available: when this Webhook fires, SOLO Server will extend the license’s Download Until date by the Days to D/L value of the product option, provided that value is greater than 0.

A quick note on terminology: the Download Until date is the primary date field on a license in SOLO Server. While the label refers to its base function of limiting file download access in the Customer License Portal, this same date can also be enforced as the license’s expiration date by your licensing client implementation. For a deeper walkthrough of configuring subscription licenses with an expiration date, see:

• Protection PLUS 5 SDK: Subscription Licenses with Protection PLUS 5 SDK covers the SOLO Server Product Option settings, the EffectiveEndDate field in the local license file, and how to enforce expiration in PLUSManaged or PLUSNative.
• Instant Protection PLUS 3: Periodic Activations with SOLO Server covers the IPP3 wizard settings for periodic expiration and how the local license file picks up the expiration date from SOLO Server during activation and renewal.

Other FastSpring Updates

• The subscription.deactivate Webhook has been updated to handle subscriptions that were migrated from a Classic to a Contextual store. Migrated subscriptions receive a new subscription ID during migration, and SOLO Server now correctly resolves these.
• The documentation for configuring FastSpring Contextual store Webhooks has been updated with an important note: do not enable the Webhook expansion option. This is a newer FastSpring setting that changes the format of the data sent to SOLO Server, and enabling it will break the integration.

If you operate a FastSpring Contextual store and haven’t reviewed your Webhook configuration recently, now is a good time to do so.

New SMTP Sender Email Controls for Email Deliverability

Modern email security standards — SPF, DKIM, and DMARC alignment — require that any service sending email on your behalf be authorized through DNS records on your domain. If those records aren’t in place, messages from SOLO Server risk being marked as spam, bounced, or rejected outright. We cover the full picture in our Email Deliverability in SOLO Server support article, but the short version: each domain you send from needs a one-time DNS configuration to be considered “verified.”

For SOLO Server accounts hosted by SoftwareKey, when an author’s domain has not yet been verified, we now automatically send their emails from noreply@softwarekey.com so messages still reach customers reliably, while preserving the original sender address in the Reply-To header so customer replies still go to the right place. This fallback is powered by two new web.config parameters introduced in these releases:

• SMTPGenericSenderEmail — When set, all outgoing customer emails will use this address as the From address, with the original From address moved to the Reply-To header.
• SMTPVerifiedDomainsFilePath — Specifies a path to a file listing verified email domains that are not overridden by SMTPGenericSenderEmail. Domains on this list continue sending From their original address.

If you’re on SoftwareKey-hosted SOLO Server accounts, there’s nothing to configure — we handle this for you. SOLO Server Self-Hosted customers can now use the same mechanism to centralize sending through a verified domain while carving out exceptions for any domains they’ve already authenticated with their own email provider.

Other Enhancements and Fixes

A number of additional improvements ship across the two releases:

• Bootstrap has been updated from version 3.3.7 to 3.4.1, picking up accumulated security and bug fixes in the framework.
• The product filter on the Add License page has been updated to work correctly in Safari, which has CSS limitations on HTML <select> lists not present in other major browsers.
• The Verify Email Domains page for Instant SOLO Server instances hosted by SoftwareKey now uses an increased timeout for calls to the SMTP2GO API. Certain domains were exceeding the previous default and causing the page to throw an exception.
• The Manual Request page in the Customer License Portal now properly uses and logs the remote IP address of the caller. Previously, because this page makes an internal web service call as if it were the calling application, the web server’s IP was logged instead. The fix ensures Allowed Activation IPs are enforced correctly during activation and that the database log reflects the real client IP.
• For Instant SOLO Dedicated URL instances, the active user count on the Manage Users page no longer includes SoftwareKey administration accounts.
• The SOLO_UpdateAuthorEmailDomainVerificationRequired stored procedure used by Instant SOLO instances hosted by SoftwareKey has been updated to support adding and removing critical author notes.

Read the full release notes here. And as always, we’d love to hear from you — feel free to reach out and contact us with your questions and feedback.