On 14th May, I discovered that SMS messages sent from my Simply Remind Me app since 1st March were not being delivered by my SMS provider, Textlocal.

Because they were successfully accepted by the gateway, Simply Remind Me correctly deducted the credits from your account. But the messages failed to arrive at their intended handsets.

The only explanation I can find is that Textlocal has, inexplicably, blocked the originator (sender ID) I was using: REMINDERS.

I have since changed this to S REMIND ME and all is well again.

What happened?

On 14th May, I migrated Simply Remind Me to a new server in the data-centre. Afterwards, I tested all the app’s features – including e-mail reminders and SMS reminders.

However, I did not receive the SMS reminders to my phone. I could see they were accepted by the gateway, but their status remained “unknown” and they never arrived.

Messages from another of my apps were being delivered successfully to the same phone, so the only logical difference was the originator (the name or phone number the message appears to come from.)

After changing this from the generic REMINDERS to the more specific S REMIND ME, reminders began to send – and – more importantly – arrive again.

Why did this start on 1st March?

Thanks to Simply Remind Me’s users, I have a steady stream of text messages going out every week. When I combed through my Textlocal account’s reports, I could see that messages sent since 1st March were left with a status of “Unknown.”

Textlocal’s report clearly showed messages stopped sending from 1st March

I don’t know what changed on 1st March. I wasn’t made aware of any potentially breaking changes, and I have asked Textlocal for an explanation.

Why did it take so long to notice?

The messages were successfully accepted by the SMS gateway, so no errors (and therefore no alerts) were generated.

I was even billed for them!

I receive a weekly e-mail report of sent messages, and each week all sent reminders were on there, so everything looked like it was working fine.

Is it working again now?

Yes!

On 14th May, I changed the originator from REMINDERS to the more specific S REMIND ME. I verified with a few messages to different phones that they were received and flagged as Delivered.

Textlocal’s reports now show messages as being delivered with the new S REMIND ME originator.

What happens next?

I will be contacting the affected users individually (anyone who has sent an SMS reminder since 1st March) with an explanation and a link to this blog post.

I have refunded the credit balance that was used for these reminders. You will see a “Manual adjustment” line on your credit statement and I have additionally provided 20% extra credits as an apology.

The adjustment will show on users’ SMS history as “Manual adjustment”.

In the long term, it is likely that I will be sourcing an alternative SMS provider. I am currently looking at an alternative that allows the generic REMINDER originator to be used and offers other, unique features.

Watch this space!