I work in a smaller startup (about 30 people). We rent an office space in an affluent neighborhood. The office has a very small (3ft x 3ft) "atrium" between the outer door and our office door. We do not share the atrium with anyone else; it is exclusively used to enter our office.
The outer door is not locked, the inner one is. A key pass is required to enter, or there's a buzzer set up for guests to request access.
I am a junior member of the company and have taken it upon myself to answer the door (my coworkers/bosses are quite happy with this arrangement as it means they do not need to be disturbed). I get the mail, accept deliveries, and unfortunately also have to navigate what visitors to let in and which to turn away.
The TL;DR of my question is: What can I politely say to people who show up at the door to get them to promptly state their purpose so that I can tell whether to greet them warmly and invite them in (for potential sponsors, friends of employees, interviewees, etc), or refuse entry (cold callers / door-to-door salesmen, etc)?
I must open the door to be able to talk to visitors. The office door is alarmed and can only be held open for up to 90 seconds before the alarm is triggered. This cuts my time to screen visitors down into a very tight window.
Due to the open concept nature of our office letting them in the door gives them easy access to all of the office (there is a very wide, very open "hallway" into the main room, with lots of glass-fronted conference rooms and offices lining it. Aka zero privacy). I don't feel comfortable letting people in prior to establishing motive because if they're a salesman it makes it a lot harder to get rid of them.
We're on a commercial road and our name implies that we're somewhat medically inclined. Because of these factors, we get a LOT of people coming by trying to sell us products or services. It falls on me, to quickly explain that we're not interested and politely turn them away.
We also get a lot of foot traffic from potential sponsors, interviewees, friends of employees and other people it is in my best interests to be unfailingly polite and welcoming to. However, I am often not aware they are dropping by and can't verify their legitimacy until they name-drop someone in the company that they're here to visit.
I often end up with a dialog like the below;
Me: Hello! (polite smile)
Them: Good afternoon, how are you today?
Me: Fine thanks, and you?
Them: Great, thank you. (If I'm lucky they might also add "My name is Bob Smith" like that should mean something)
(sometimes salesmen will quickly launch into a speech here but more often than not the visitor will attempt to step forward into the doorframe, expecting me to let them in. I stand my ground and it's off-putting for both parties)
Me: ... What can I do for you?
Them: I'm here to meet with X. (or) I'm with Y company selling Z.
And then I can let them in / turn them away. etc.
I was always taught not to give my name out because it encourages solicitors, but I also find that a lot of the interviewees try to be chummy and ask for names so I can't use that as a barometer, and then my first interaction with a potential new employee is me giving out my name so reluctantly it's like I'm giving away my firstborn.
I basically have a 90-second window to a) exchange polite greetings and b) figure out why they're there, all while being polite-but-firm to potential solicitors without coming across as rude to guests.
I'm not a professional assistant and I have zero experience as a greeter. I imagine there's a simpler/more effective way to run this dialog which is why I'm reaching out here.