I've tried several different iterations of this same search query but I cannot find a member based on either userName or email. I assume it has something to do with the @ character in the search. I've also searched google and this forum and can't find anyone who has documented this process. I can find members quickly using any other property value except for the email address in the userName or the email fields.

Does anyone know how to accomplish this search process? While using email as userName for members? This is my code, and when passing in an exact match for email address I cannot get any of the queries to return a matching member.

long totalRecords;
string methodUsed = "GetMembersByPropertyValue email";
var membersList = memberService.GetMembersByPropertyValue("email",studentEmail.ToString().ToLower().Trim()); 
    membersList = membersList.Count() == 0 ? memberService.GetMembersByPropertyValue("userName",studentEmail.ToString().ToLower().Trim()) : membersList;
if(firstName != null && firstName != "")
{
    methodUsed = "GetMembersByPropertyValue firstName";
    membersList = memberService.GetMembersByPropertyValue("firstName",firstName.ToString().ToLower().Trim(), global::Umbraco.Core.Persistence.Querying.StringPropertyMatchType.Contains);
}
if(lastName != null && lastName != "")
{
    methodUsed = "GetMembersByPropertyValue lastName";
    membersList = memberService.GetMembersByPropertyValue("lastName",lastName.ToString().ToLower().Trim(), global::Umbraco.Core.Persistence.Querying.StringPropertyMatchType.Contains);
}
if(studentID != null && studentID != "")
{
    methodUsed = "GetMembersByPropertyValue colleagueId";
    membersList = memberService.GetMembersByPropertyValue("colleagueId",studentID.ToString().ToLower().Trim(), global::Umbraco.Core.Persistence.Querying.StringPropertyMatchType.Contains);
}
if(membersList.Count() == 0 && studentEmail != "")
{
    methodUsed = "GetMembersByPropertyValue userName";
    membersList = memberService.GetMembersByPropertyValue("userName",studentEmail.ToString().ToLower().Trim());
}
if(membersList.Count() == 0 && studentEmail != "")
{
    methodUsed = "GetAllMembers userName || email";
    membersList = memberService.GetAllMembers().Where(x => x.GetValue("userName") == studentEmail || x.GetValue("Email") == studentEmail);
}
if(membersList.Count() == 0 && studentEmail != "")
{
    methodUsed = "GetAll() userName || email";
    membersList = memberService.GetAll(0, 999, out totalRecords).Where(x => x.GetValue("Email") == studentEmail.ToString().ToLower().Trim() || x.GetValue("userName") == studentEmail.ToString().ToLower().Trim());
}
<div class="container-fluid">
    <div class="row overflow-auto">
        <h3>@membersList.Count() Members matching @Html.Raw(studentEmail) methodUsed: @methodUsed</h3>
        <table class="table table-striped table-bordered table-hover">
            <thead>
                <tr>
                    <th>Umbraco ID</th>
                    <th>First Name</th>
                    <th>Last Name</th>
                    <th>User Name</th>
                    <th>Email</th>
                    <th>Last Update</th>
                    <th>Time</th>
                    <th> </th>
                </tr>
            </thead>
            <tbody>
            @foreach(var thisMember in membersList)
            {
                var exsitingMember = Umbraco.MembershipHelper.GetById(thisMember.Id);
                bool setColleagueId = false;
                string existingPswd = exsitingMember != null ? exsitingMember.GetProperty("existingPasswordB64").GetValue().ToString() : String.Empty;
                string existingPswdDecrypt = existingPswd != String.Empty ? FresnoUtilities.Classes.Base64Encode(existingPswd) : String.Empty;
                    <tr>
                        <td><a href="/umbraco/#/member/member/edit/@thisMember.Key" target="_blank">@thisMember.Id</a>
                        </td>
                        <td>
                            @exsitingMember.GetProperty("firstName").GetValue().ToString()
                        </td>
                        <td>
                            @exsitingMember.GetProperty("lastName").GetValue().ToString()
                        </td>
                        <td>
                            @exsitingMember.GetProperty("userName").GetValue().ToString()
                        </td>
                        <td>
                            @exsitingMember.GetProperty("email").GetValue().ToString()
                        </td>
                        <td>
                            @exsitingMember.UpdateDate.ToString("M/dd/yyyy")
                        </td>
                        <td>
                            @exsitingMember.UpdateDate.ToString("hh:mm tt")
                        </td>
                        <td>
                            @if(existingPswdDecrypt != String.Empty)
                            {
                                <form method="post" target="_blank">
                                    <input type="hidden" name="userName" value="@exsitingMember.GetProperty("email").GetValue().ToString()">
                                    <input type="hidden" name="userPassword" value="@existingPswd">
                                    <input type="submit" name="loginAs" value="Login As">
                                </form>
                            }
                        </td>
                    </tr>
                    }
            </tbody>
        </table>
    </div>
</div>