'I really hated my colleague. Then she hacked into my Slack account.'

Daniella* had two siblings who never answered her calls. 

It didn't matter what time of day, whether they were in the room next to her or hundreds of kilometres away. It could have been an emergency or a question about something as innocuous as the weather — because rain, hail or shine, they were going to leave their phones buzzing whenever she attempted to dial them up. 

I had no idea why they treated her with such disdain and apathy until a few months later, when I developed those very same feelings.

Watch: When you see colleagues outside of work. Post continues after video. 

Once upon a time, Daniella and I used to be colleagues. 

I was a junior producer fresh out of university, about as excited as one could possibly be to start a real job. Then I met her. She looked me up and down, not meeting my eyes, before squarely staring at my bare shoulders. 

"I'm Daniella," she told me with a curt smile, eyes darting from her computer monitor to me. It was her first day too, but she had gotten there 45 minutes early as she was my "superior", she later told me. She needed to set a good example for her junior colleague. 

I was barely 20 years old and excited to have a work friend. What a mistake that was.

We started talking about work, about our mornings. Eventually, she wanted to grab lunch, walk to the station together and even stroll into work together, She asked me where I got my clothes from and would show up to the office a few weeks later wearing the same shirt as me. I knew something was off, but I ignored it. 

She told me about her family, how they ignored her calls, how her step-parents didn't like her much and how she couldn't understand why. 

I didn't at first either. 

Read more: "I wasn't allowed to laugh." 37 women on the weirdest thing they ever got in trouble for at work.

Daniella told me she hated our boss. She thought she could run the place better. She told us her ideas were better. I'd cringe every time but the people-pleaser in me didn't say anything. I shrunk in her presence. 

Another colleague, a nice girl named Sumi, noticed it. She took me under her wing. 

We chatted about our feelings. Eventually, our words turned cruel. Every time Daniella said something uncalled for, or something racist or sexist, we'd debunk it in our private work chats. We rolled our eyes when she couldn't see. We started walking home together. We gossipped about her on the train together. 

At first, it was innocent. We were shocked to know such a person. 

Then it turned malicious. We'd comment on everything she said, even what wasn't hurtful or problematic. We grimaced when she entered the room. No one from outside of work believed our stories about Daniella, so we turned to one another.

Our friendship was born out of a complicated situation and a desperation to understand this person we were working alongside. A person who was so deeply problematic. 

Listen to this episode of No Filter on the big secret of female friendship. Post continues after audio. 

Eventually, Sumi resigned. She had found a better job with more money and better opportunities. Daniella wondered aloud how someone like our colleague could get a better job when she "lacked in skills". 

Sumi flinched and then began writing the most heinous, 200-long-word message to me about what exactly she thought of Daniella. 

I wrote back... words that should never be repeated. We typed with a fury that day, for hours. It felt almost wrong to stop. 

Daniella resigned a few weeks after Sumi left. She turned colder towards me and on her last day, she wished me luck and hoped the place wouldn't turn to s**t with her leaving. 

She blocked us on Instagram. I stopped checking her LinkedIn for updates and I found a new job too. Life moved on. 

Three years later, I got a message from Sumi. 

"Someone who worked with Daniella says she caught us bitching about her," the message read.

I laughed, then pouted, then remembered something: My work Slack account glitched back in the day, and I was briefly logged out. I hadn't realised at the time, but it was probably because someone else had logged in. As me.

It had to be her. It had to be Daniella.

We all had similar passwords, and I knew that was how she managed to get in; it was the most obvious answer. 

At first, I didn't feel bad. I thought the way I felt was incredibly fair – but now I'm no longer 20 years old and not nearly as desperate for friends. 

I know what appropriate workplace conduct looks like now. 

I know how to say something if I'm uncomfortable, or at least the correct avenues to go down if I don't. 

Basically, what I did to Danielle — the intense, cruel gossip — was the wrong thing to do. 

I've learnt many lessons from my first job but the most important one by far has nothing to do with my actual work. It's all about the people I work with.

Don't gossip about your work colleagues, but if you must... do it in person. 

Trust me.

Feature Image: Getty.