Readdle Avis 

Great customer service, personalised response, very considerate. A great suite of products filling niches with good utility.

I bought a licence of PDF Expert for Mac in 2017.
I used this tool for some years, nice to have.
Today, I had to reset my hard drive and reinstall PDF Expert, but they can not confirm the license code to activate the app.
I can't use it anymore.
Great...

I’ve been a Spark Premium subscriber for several years, using it daily for critical business and client communications. Unfortunately, the app has gone sharply downhill, and Readdle’s handling of issues has been extremely disappointing.

1. Paid "Bug" Features Removed Without Notice
Spark quietly removed Read Statuses (read receipts) from my active Premium plan — a feature I relied on for over a year. Support later claimed it was a “bug” that I had access at all, and informed me it now requires the far more expensive Pro plan. Removing an existing paid feature and re-locking it behind a higher tier feels misleading and unethical.

2. Serious, Ongoing Bugs
Spark has repeatedly sent scheduled emails even after I deleted them — more than five times — including sensitive reminders to clients. This caused real reputation damage and embarrassed me professionally.
On top of that, the app crashes frequently on both iOS and Windows, often while I’m writing important emails, wiping out drafts. Sync delays, random freezes, and unreliable search add to the frustration.

Its just an unstable and unreliable application - not a device related issue its a software related issue - when they send app updates 1-2 a week expect instability.

3. Support Has Not Provided Real Solutions
Despite months of tickets and follow-ups, support has not resolved any of these issues. I mostly received generic responses, no accountability, and no timeline for fixes - I've reported 5-7 major bugs.

Today, it’s unstable, unreliable, and feels like it’s being monetized aggressively at the expense of long-time customers. I can no longer recommend it to anyone who needs dependable email for business.

Avoid this product.

I can't believe I'm saying this about Spark Email, but after using it for five years, they have managed to make it so bad that it's hardly usable! All the nonsense AI features are so annoying, and the new design is messy and uncomfortable. I'm so disappointed!

Distinctly average product but when to comes to support they really fail. Spark Mail is by Readdle

From Readdle Team rdsupport(at)readdle.com
Thank you for contacting Spark Support Team. We really want to help you. But, because of the high volume of requests, we read your feedback but can’t reply personally to each email. We’re sorry, and we’re currently working on a better solution.

When you're seeking support that is an utterly shameful response

Good solid product company of my school / college friends which now appears to be a very successfull startup, which finally reach 100M downloads in total within whole set of it's applications. It's all started in 2007 year, when iOS was only released, damn 12 years passed!!!!