I've never had any dealings with author.me, but I do have a little experience with submittable.com.
I have no qualms about using submittable.com, but you'd have to decide for yourself once you feel you have enough information to make that decision.
Submittable.com seems to be used by quite a few legitimate literary journals, magazines, and small presses, and it's been around for at least 10 years, as evidenced by some of the work I submitted through the service.
Click on the image file below this post to get a look at what an author's file page (mine) looks like.
You'll see that I have 5 short-story submissions on there between 2008 and 2018. I've redacted my name and the names of the stories in this file, but you can see the publishers' names, the submission dates, as well as tabs above you can click on for the current status of the submission. To the right of each entry is a button to withdraw an active (no decision yet) submission, or remove a submission that has been declined. Your work won't be up there forever if you choose to remove it.
I've never had the sort of backlash you are worried about from submittable.com. In fact, I ended up with spam -- electronic and postal -- from other literary journals
only when ordering a subscription and they sold their subscription list to other literary journals.
I encoutered submittable.com by using Duotrope.com, which has more than 6,000 markets for short stories and small presses you can submit directly to -- much like QueryTracker lists agents. Both Duotrope and QT offer search and tracking features. Sub.com is a way for publishers to handle what you have submitted and for you to follow what's happening with with your submission. I imagine that agents use sub.com in a comparable way. It has been a few years since I tried to market short stories. Started again, and I'm seeing a big increase in the number of journals and magazines requiring "submittable.com" as a way to upload your story to a particular publisher.
There seems to be a big difference between author.me and submittable.com.
I wouldn't go near author.me, which is basically a way for agents to browse what authors have to sell, and then contact the authors to say they're interested. To understand what's so awful about this, it would be helpful to read agent Janet Reid's post, as suggested by
jc writes on this thread. I'll repost the link:
http://jetreidliterary.blogspot.com/2016/01/authorsme-query-service.htmlSubmittable.com offers publishers a service as described here:
https://www.submittable.com/submission-management-softwareClick on the video triangle for an overview.
For a publisher or agent, there are several advantages to using submittable.com. For example, this takes away one of the biggest risks -- directly receiving attached files in an email that may contain a virus. An editor I have submitted my story to can read my story online without downloading it, as well as record any actions related to a submission, which authors can learn about by logging in.
As far as I can tell, only I and the publications I've chosen to submit my story to can read my story on submittable.com.
It isn't up there (like on the author.me site) for the perusal of anybody out there looking for stories to publish.
There is no advantage for an agent to pay to use author.me rather than the traditional submission process. Authors who buy into authors.me, in order to avoid the work and research of submissions, are, in my opinion, doing the equivalent of standing on a hilltop and throwing their manuscript pages to the wind. Nobody is going to read them. Agents already have plenty of submissions targeted according to their own submission guidelines.
I'm surprised that an agent you thought of querying would ask you to sign into authors.me.
Is this agent listed on QueryTracker?
Regarding your concern about including your address just to submit a query, I have always thought of that as standard for a business letter, which is what a query is. My query always includes my street address, email address, and phone number.