Outlook users: Discover 4 key benefits in Rocketseed’s new Microsoft 365 add-in release

By Janine Ferenčak

New outlook – new email signature opportunities

Email is at the heart of your daily business communications. With Microsoft 365 rolling out the new Outlook – and sparking plenty of debate – it’s a pivotal moment for organizations. While some users are cautious about switching, others are already embracing its streamlined interface, AI-powered features, and deeper Microsoft 365 integration. This creates exciting opportunities to ensure your team’s email signatures are not only consistent and professional across every device but also fully optimized for the new Outlook’s capabilities.

At Rocketseed, we’ve been listening to IT teams, marketing managers, and everyday users. The result is Rocketseed Microsoft 365 Add-In v1.6.0, built on Signature on Compose – the ability to see your email signature in the compose window before sending. This upgrade takes that core capability further than ever, optimized for the new Outlook and delivering four game-changing benefits for email signature management.

If your team is still on Outlook classic, Rocketseed keeps signatures applied correctly there too, ensuring smooth transitions without compromising branding or compliance.

Let’s explore the key add-in features and benefits for the new Outlook.

4 Key features (and Benefits) of Rocketseed’s Microsoft 365 add-in upgrade

1. Confidence on the go: signature on compose for mobile

Want to ensure your email signatures look perfect before you hit send—even on mobile? For the first time, Rocketseed’s Signature on Compose is available in the Outlook mobile app for iOS and Android. With this add-in upgrade, you can preview your branded email signature directly in the compose window, giving you complete confidence that every email looks polished and on-brand, whether at your desk or on the move.

This feature directly answers the demand from users who need professional, consistent signatures while sending emails on the go.

To enjoy this benefit, ensure that your team is using at least Outlook iOS v4.2527.0 or Android v4.2524.1 (42524820).

“With full support for Microsoft 365 and Outlook mobile apps, users can now see exactly how their email signature will appear before sending, ensuring brand consistency, especially on mobile. Meanwhile, embedded image support guarantees a perfect display for recipients.”

Janine Ferenčak, Managing Director, Rocketseed

2. Flawless display for every recipient: embedded image support

No more downloading before images display. This marks a significant improvement over the old referenced-image method on mobile devices, which was the only option until the recent update to the Microsoft API. Our add-in now supports embedded images so all visual elements of your email signatures — logos, banners, and social icons — that you see when composing display instantly and correctly to recipients, with no downloads required.

The result? Every recipient sees your branding exactly as intended, on any device. It makes your signatures more professional, delivers a powerful first impression and drives engagement.

3. Faster performance and reliability: image caching

Delays and missing signatures when composing emails are a thing of the past. Our add-in now caches signature images and HTML locally within the Microsoft 365 environment. This means that, should the server be temporarily unavailable for any reason, the signature will still be available locally and shown in the compose window. It also means the signature is populated and injected into the mail body much more quickly, improving performance.

4. Always the right signature: support for multiple “from” addresses

Does your team have employees using multiple mailboxes?  Now, when they switch between mailboxes, the new add-in automatically applies the signature that is assigned to the newly selected ‘from’ email address. This is especially useful for those who also have responsibility for a departmental (eg. accounts@) email addresses, or executive assistants composing and sending emails on behalf of executives. This feature ensures every message carries the right identity and branding, without manual intervention. (Please note: not currently supported on Outlook mobile.)

Implementing the upgrade

These Rocketseed updates are available exclusively for Microsoft 365 users. Your company’s Microsoft 365 administrator needs to request a manifest file from Rocketseed to deploy the new functionality organization-wide.

For organizations using a mix of Outlook versions, Rocketseed can deploy both the new add-in and the previous version simultaneously. Classic Outlook users can continue as before while new Outlook users enjoy the full benefits. Unlike other providers, Rocketseed works with you to find a solution that fits all teams.

Why Rocketseed is the foundation for Office 365 email success

Rocketseed isn’t just an add-on. It’s the signature layer that brings branding, compliance, and marketing directly into every email sent from your Office 365 environment.

• Centralized control – Manage signatures across all users, devices, and locations from a single cloud dashboard. Explore Rocketseed’s centralized business email signature management platform.
• Consistent branding – Lock in fonts, colors, logos, and contact formats for a polished, professional look.
• Accurate contact details – Automate employee contact details in email signatures synced from Microsoft Entra ID.  
• CRM-ready banners – Add clickable marketing banners and sync engagement data with platforms like Salesforce and HubSpot. Check out Rocketseed’s CRM integration features.
• Compliance-ready – Automate disclaimers, prevent user edits, and align with industry regulations. See Rocketseed’s compliance and security capabilities. 
• Built for Microsoft 365 – Cloud-native, tamper-proof, and designed for seamless integration into Office 365 and hybrid deployments.

With Rocketseed, every email becomes a brand asset – professionally styled, compliant, and performance-optimized.

Why upgrade now

Rocketseed’s Microsoft 365 Add-In v1.6.0 takes Signature on Compose to the next level. With mobile previews, embedded images, reliable local caching, and shared mailbox support, it delivers a superior experience for both senders and recipients while leveraging the opportunities created by the new Outlook.

To enable the upgrade and maximize these benefits for your organization, contact Rocketseed today.